US716870A - Process of casting finished pinions or gear-wheels. - Google Patents

Description

L. J. CRECELIUS. 'PROCESS 0F CAS FINISHED PINIDNS 0B GEAR WHEELS.

Y Application Jxvmu B, 1901. Renewed Oct. 2D, 1902.)

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No. 716,870A

Patented'ec. 305 1902.v L. J. CRECELIUS; v PROCESS 0F CASTING FINISHED PINIUNS 0R GEAR WHEELS. Y

(Applicatian fIedJune 8, 1901. Renewed Oct.-20, 1902.)

(No Model.)

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UNITED STATES PATENT OEEICE.

LOUIS J. OREOEI.|IUS,,VOF` ST. LOUIS,A MISSOURI, ASSIGNOR OFONE-I-IALF TO WILLIAM GRAYSON, OF ST. LOUIS, MISSOURI.

PROCESS OF CASTING FINISHED PINIONS OR GEAR-WHEELS.

SPECIFICATION forming part Of Letters Patent N o. 716,870, dated. December 30, 1902. Application tiled June 8, 1901. Renewed Gotoher 20, 1902. Serial No. 128,083. (No model.)

To a/ZZ whom tm/ty concern,.-

Beit known that I, LoUIs J. CRECELIUS, of the city of St. Louis, State of Missouri, have invented certain new and useful Improvements in Processes of Casting Finished Pinions or Gear-Wheels, of which the following is a full, clear, and exact description, referenceV A further object of my invention is to pro' duce such pinions and gear-Wheels with an accurately-finished face primarily and solely by the casting operation.

A further object is to produce said pinions and gear-wheels devoid of the usual shrinkage, and yet having accurately spaced and finished teeth and other accu rately-nished parts primarily and Vsolely by the casting operation.

A further Objectis to produce said pinions and gear-wheels having a shell or skeleton of metal, such as bronze or steel, and the same having cast within themselves'an annular core of refractory material which shall act to reinforce or strengthen said shell and greatly lightenand cheapen the same.

improved molding-flask made use of.

Figure l is a sectional side elevation of the Fig. 2 is a similar view having the master-pattern in position therein and also showing the improved rammer in use. Fig. 3 is a plan view of the said ask. Fig. i is aplanvicw of the parts shown in Fig. 2. Fig. 5 is a sectional side elevation showing the flask' after the same has been rammed and illustrating the said master-pattern in the act of being Withdrawn. Fig. 6 is a similar view of the rammed ask having the annular core supported therein. Fig. 7 is a view identical with the last,

except that it has a'tapered mandrel in posii tion therein. Fig. 8 is a view identical to the last with the exception that the gate and spreader are applied to thelfiask and the casting has been poured, the same being still located Within the flask. Fig. 9 is a sectional plan view of a finished pinion or gear-Wheel.

l indicates a cylindrical ask,preferably Ina-de of metal, and fitted within its-lowerend isa head 2, the inner face of which is bored and turned accurately and highly polished to act as a mold-surface for one face of the pinions or gear-wheels to pbe cast thereon. Within this dask I next placca preferably metallic master-pattern 3, having a length considerably in excess of the depth of said flask and having machine-cut teeth Llof the properpitch and cou ntersunk at its lower end, whereby it may be accurately fitted upon the raised center 5 of said head 2 and whereby the act of placing said pattern will also center it With'relation to said center. Next I proceed to ram the ask in the manner shown in Fig. 2 by placing a body of refractory pulverulent material 6--say refractory carbon-Within the annular space about said master-pattern and ramming the same by means of the annular rammer 7. Said rammer 7 has an external diameter corresponding to the internal diameter of said ask and is vprovided with a series of internal radial projections 8, which occupy the space betweenf the teeth 4 of said master-pattern during the act of ramming. Said rammer is provided with opposite vertical handles 9, .by means of which it may be lifted during use. After the ask has been fully filled the master-pattern 3 is withdrawn, as shown in Fig. 5, and then I place within the moldV so formed an annular core 10, preferably made of some refractory material, such as common tire-clay, and this hassuitable projections 1l at its ends for supporting it within the mold, so that when the .metal is poured said metal may pass upon all sides of said core. Said core 10 has a tapered internal passage, in which is next placed the tapered metallic mandrel 12, which latter accurately iits said tapered passage, and which mandrel is pro vided with a lateral projection 13, which projects toward a corresponding recess in said core, so as to form a key-seat in the pinion or IOO gear to be cast. Said mandrel may of course be accurately finished and highly polished and preferably provided with a coating of suitable fireproof lubricant. I prefer graphitic carbon. It will be noted that said mandrel fits accurately the center bore of said head 2, which acts as a rigid support therefor. Mounted upon the upper end of said mandrelis a conical spread er 14, and mounted upon the upper face of the mold as finished is a common gate 15. The mold is now ready to be poured. However, prior to pouring, the entire mold, as shown in Fig. 8, is lifted b v means of its projecting ears 16 and placed within a suitable furnace and heated to about 900 Fahrenheit and then quickly withdrawn and the metal poured therein, and while the metal is still fluid within the said mold I apply pressure thereon by means of any common press, and thereby slightly compress said fluid metal. This compression solidifies the iiuid metal in the mold, and thereby causes every part of the casting to shrink uniformly. Finally the gate 15 is removed, the casting is removed from the mold, and its upper end is sawed off at a suitable point. The finished product is shown in section in Fig. 9. The finished product is indicated in Fig. 9 by the numeral 20, and it is provided with the filling or core 10, as above described, and has of course the tapered bore 21, having the keyseat 22, which latter is formed by the lateral projection 13 of the said metallic mandrel 12.

Of course it will be understood that the mandrel 12 should be removed after'the end of the casting has been sawed off.

The advantages possessed by my invention are as follows:

First. I obviate the usual verylarge amount of labor required in producing machine-cut pinions and gears, and I produce a finished article direct from the mold.

Second. By my process I retain the strongest of the metal, which, as is well known, is always on the surface of castings.

Third. By making use of the annular strengthening-core Within the casting I am thus enabled to dispense with fully one-third of the metal usually required and substitute therefor much lighter and cheaper material. The advantage of lightness `in a high-speed pinion is well understood. In this connection I desire to state that I have found that in a core made of fire-clay or similar substances when burned prior to placing within the mold and then reheated, as described, the liquid metal will fill all the interstices of said core and firmly adhere, and thus make a solid mass of the core. The article thus cast will be found practically as strong as if it had Ybeen cast of solid metal.

Fourth. By slowly pouring the liquid metal into the heated mold, which permits all gases to develop and be discharged as the pouring proceeds, thereby preventing all blow-holes, honeycombs, dac., and assures an absolutely dense casting.

I do not herein claim the product of my improved process, as I have made the same the subject-matter of a copending application, tiled October 7, 1901, Serial No. 77,790.

I claiml. The herein-described process of casting finished pinions and gear-Wheels, which consists in rst, forming a flask with a metallic head at its lower end turned and polished accurately and provided with a raised center 5 and a central bore; second, forming a metallic master-pattern with accurately-finished peripheral teeth and a counter-sunk recess at its lower end; third, mounting said masterpattern in said flask, so that said mold-surface will fit within said countersunk recess of the master-pattern; fourth, placing a body of refractory carbon Within the annular space about said master-pattern and simultaneously ramming said refractory carbon into all the spaces between the teeth of said master-pattern by means of an annular rammer; fifth, removing said rammer; sixth, withdrawing said master-pattern; seventh, mounting Within the central bore of said flask-head a tapered metallic mandrel provided with a lateral projection to form a key-seat in the casting; eighth, mounting aconical spreader upon the upper end of said metallic mand rel; ninth, mounting a gate upon the upper face of the finished mold; tenth, heating the mold to about 900o Fahrenheit, and pouring molten metal into the mold while the same is thus heated; substantially as specified.

2. The herein-described process of casting finished pinions and gear-wheels, which consists in rst, forming a iask with a metallic head at its lower end turned and polished accurately and provided with a raised center 5 and a central bore; second, forming a metallic master-pattern with accurately-finishedperipheral teeth and a countersunk recess at its lower end; third, mounting said master-pattern in saidfiask, so that said mold-surface will fit within said countersunk recess of the master-pattern; fourth, placing a body of refractory carbon within the annular space about said master-pattern and simultaneously ramming said refractory carbon in all the spaces between the teeth of said masterpattern by means of an annular rammer; fifth, removing said rammer; sixth, withdrawing said master-pattern; seventh,mount ing within the central bore of said ask-head a tapered metallic mandrel provided with a lateral projection to form a key-seat in the casting; eighth, mounting a conical spreader upon the upper end of said metallic mandrel; ninth, mounting a gate upon the upper face of the nished mold; tenth, heating the mold to about 900 Fahrenheit, and pouring molten metal into the mold while the same is thus heated; and finally, applying pressure to the molten metal while in a fluid state within said mold; substantially as specified.

3. The herein-described process of casting finished pinions and gear-wheels, which con- IOO siste in rst, forming a flask With a metallic head at its lower end turned and polished accurately and provided with a raised center 5 and a central bore; second, forming a metallic master-pattern With accurately-finished peripheral teeth and a eountersunk recess at its lower end; third, mounting said master-pattern in said flask, so that said mold-surface will t Within said countersunk recess of the master-pattern; fourth, placing a body of refractory carbon Within the annular space about said master-pattern and simultaneously ramming said refractory carbon into ail the spaces between the teeth of said master-pattern by means of an annular rammer; fifth, removing said rammer; sixth, Withdrawing said master pattern; seventh, placing Within the mold an annular core of fire-clay, having suitable projections at its ends for LOUIS J. CRECELIUS.

Witnesses:

ALFRED A.'EICKS, J oHN C. HIGDoN.

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