US1264338A - Method of making cast-metal car-wheels. - Google Patents

Description

C. SHERMAN.

METHOD 0F MAKING CAST METAL CAR WHEELS. APPLICATION FILED. Nov. 22. 1917.

l y 6% 3 3 m Eatented Apr. 30, 1918.

2 SHEETS-SHEET I.

C. W. SHERMAN.

METHOD OF MAKING CAST METAL CAR WHEELS. APPLICATION FILED Nov. 22, |911.

Patented Apr. 30, 1918.

2 SHEETS-SHEET 2.

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'-CLIFTUN W. SHERMAN, 0F BUFFALO, NEW YORK.

f Mn'ri'ion or MAKING caer-METAL cnn-WHEELS.

Lacasse.

Specification of Letters Patent.

Patented Apr., 30, 1913.,

Original application filed. November 3, 1914, Serial No. 870,057. Divided and this application led November To all whom t may concern:

Be it known that I, CLIFTON W. Sinn:- MAN, a citizen of the United States, residing at Buffalo, in the county of Erie 'and State of New York, have invented new and useful Improvements in Methods of Making Cast- Metal Car-Wheels, of which the following is a specification.; y

This invention relatesto an improvement in the method 'of making cast metal car wheels.

'Ihe invention has for its object the production of cast car wheels in which the formation of the different sections is suchthat the bearing surface of the tread or rim is hard, so as to increase its wearing capacity,

the bore of the hub is soft to permit of easilyl machining the same in order to properly fit the axle; to distribute the metal to the supporting plates and brackets forming the body which are of smaller sectional area A than the hub and rim, so as to produce a casting without shrinkage strains, spongy spots or other deformationlwhich would impair the strength of the casting and to eliminate formation strains.

This application is a divisionof an application filed by myself November 3, 1914, Serial #870,057. i

In the accompanying drawings:

Figure'l is a vertical section of a molding flask for producing a car wheel in accordance with my invention, taken on line 1 1, Fig. `2. Fig. 2 is a horizontal section taken on line 2-2, Fig. 1. p ,Fig. 3 is a vertical section of a car wheel 'embodying my improvements, taken on line33, Fig. 4. Fig. 4 is a bottom plan view thereof.

Similar characters of reference indicate corresponding parts throughout the several its lower edge with a laterally projecting annular flange 37 and a body or supporting member connecting the hub and rim. The

' upper unflanged edge of the rim is arranged higher or above the upper end of the hub,

as shown in Fig. 3. Although the body or e supporting member may be variously constructed so far as the details are concerned,

that shown in the drawings is suitable and Serial No. 203,310..

lis dished downwardly and connectedl at the outer edge of its. elevated outer part 4 with the upper unfian-ged edge of the rim while the inner edge of the inner depressed part 5 of said plate is connected with the upper end of the hub, an annular row of outer brackets 6 connecting the underside of the plate with the rim and terminating at their inner ends short of the hub and an annular row of inner brackets 7 connecting the underside of said plate with the hub and terminating at theirouter ends short of the rim.

In addition to the innerV and outer brackets the plate is preferably providedon its underside with an annular row of intermediate brackets 8 which terminate at their interspaced relatively to each other andthe inner ends of the outer brackets and the outer ends of the inner brackets overlap each other,l while the intermediate brackets overlap .the opposing ends of the inner'and outer brackets, as shown in Fig. 4. 'Ihe outer brackets are preferably so constructed tliatthe sectional area of the same gradually increases from the outer ends toward the inner ends thereof, the inner brackets gradually increase in sectional area from their inner ends toward their outer ends, the intermediate brackets gradually increase in sectional area from their outer and inner ends to-ward the central parts of the same, as shown in Fig. 4, andthe plate gradually increases in sectional area `from its inner and outer edges to that part thereof intermediate of its inner and outer edges, as shown in Fig. 3. l

If desired, the plate may also be provided with an annular strengthening bead 9 which is preferably arranged on the upper side between the hub and rim and formed with the outer brackets, the inner brackets, and the intermediate brackets. Fach of the brackets is further preferably provided on itsopposite sides adjacent to said bead with swells or ribs, as shown at 6, 7a, 8a, for a purpose which will presently appear. The various elements of the wheel just described are all formed integrally. p

VVithin the bore of the hub the same is provided with aninner chill, lining or tool piece 10 rpreferably of tubular forni and lcon,-

'ferred construction of hub lining this is structed of soft or low carbon steel. rlhis lining is preferably secured ,to the hub b placing the lining within the mold in Whic the cast parts of the wheel are formed, so that a fused" joint is produced between the v hub and lining which knits the same together as effectively as though the same -were constructed in one piece of metal. To

further secure the hub and lining against longitudinal displacement relatively to each `other the periphery of the lining is provided with a plurality of laterally projecting members 11 which are preferably in the form of annular ribs, flanges or collars and which are embedded in the metal of the hub so that the lining is securely anchored against displacement. Ordinarily the pouring of mol' ten metal against or around cold metal, as occurs when pouring metal against the metal hub lining, would produce cracks in the casting owing to the expansion of the cold metal which prevents proper shrinkage of the casting. rl`his difficulty is overcome in the present instance by making the hub lining collapsible or contractible and in the preaccomplishedwby making the same of a -plurality of sectionsJ which are separated fromeach other by longitudinal joints 10, the space or gap at each of these joints being `bridged by a longitudinal flange 11a arrim and flange are also made solid and hardened by pouring the metal forming these parts against a heavy chill.v .The na-v ture of the metal forming the rim"section v of the Wheel isv such as to produce hardness or lend itself to be hardened under proper heat treatmentV and rapid cooling. Owing to the above described -construction-of the' wheel, the formation of the flanged rim is effected rapidly and uniformly while the pouring of the metal proceeds at a uniform rate into the mold at the hub, and during such pouring, the formationpf the flanged rim does not begin until practically the en.- tire hub and the inner parts of the body are formed comprising'the depressed inner part of the plate, the inner brackets and the intermediatebrackets. i

A mold suitable `for producing this wheel is shown in Figs. 1 and 2 and as there shown,

`the same comprises a bottom plate 12, a-drag or nowel 13 filled with sand and resting'on the bottom plate and forming the lower section of the molding flask, a cope 1 4 filled with sand and forming the upper section of the flask, an iron chill or chiller 15 arranged between the drag and cope and forming the intermediate part of the flask, and a core 16 arranged centrally in the flask. The lining 10 is placed in the mold around the core 1G, the joints between the lining sections `at the upper and lower ends thereof being closed by the adjacent parts of the sand in the flask and the outer longitudinal edges of these joints being closed by a wash of clay or the like.. The fluid metal is poured into the cavity formed between the several flask members through a gate or sprue 17 which is formed in the central part of the cope and opens into the upper end of the hub section of the mold cavity.

The outer chill ori chiller 15 preferably forms that part of the mold which extends from the back or upper side of the rim` flange upwardly across and above the load line 18 of the wheel so that the bearing surface of the flange and the adjacent part of the bearing surface of the rim which receives the wear of the load is densely formed andl hardened.

At a suitable number of places the cope of the molding flask may be provided with risers 19 which open into the mold cavity at the lheaviest sectional area of the brackets and plate. This heavy sectional area can be located at any suitable point between the rim and the hub, it being the aim to keep this area of metal molten or in a pasty con* dition until the heavier rim and hub sections have congealed with the assistance of the Chillers 10 and 15 and in this way assist in relieving the strain on the lighter plate and bracket sections.

A s the moltenl metal is poured through the sprue into the mold cavity, the same first enters the hub cavity and'begins filling the latter from its lower end upwardly. After the lower .end of the hub has been formed the continued rise of the metal then begins the formation of the inner brackets and by the time the metal reaches the top ofthe hub cavity the depressed inner part of the plate and the intermediate brackets have been formed. Up to this time the metal has not yet entered the rim cavity and no part of the rim or its flange and adjacent parts have been formed. As the molten metal surrounds the cold hub lining or chill, the latter becomes heated and tends to expand but owing to the slack joints between the sec- .tions ofthe lining, the latter is contracted aan,

elevated ends bf the outer bracket cavities, the continued inflow of metal through the sprue. causes the metal thenceforth to flow rapidly downwardly and outwardly through theouter bracket cavities and lill the rim cavity so that the. rim quickly forms with the outer brackets and when the metal reaches the top of the rim the outer elevat led part of the plate and the adjacent part of the intermediate brackets have also been filled. ln this manner the inner part of the lwheel will be formed first followed by the or head of molten metal.

The above described quick and uniform formation of the flanged rim section is se.- cured while themolten metal enters the mold cavity at a uniform rate throughout the casting operation.

'llhe metal y lyingagainst the rim chill and hub chill shrihks, solidifies and contracts iirst i and the plates and brackets and inner side of rim Iand outer side of hub sections are properlyv fed' by the head or surplus of reserve molten metal in the risers which flows from the same outwardly through the outer brackets and outer parts of the plate, bead and intermediate brackets to the rim, and inwardly through the inner brackets and inner 4parts of the plate to the hub, thereby compensating or allowing for any shrinkage and contraction in the metal forming the plate, rim and hub and preventing the formation of any defects which would weaken or aHect the strength of the wheel, such as shrinkage holes7 spongy spots or piping. rllhe pressure of molten metal tends to strain the congealedy circular rim section. This combined with the resistance of the congealed plate section during the cooling periodftends to form vertical cracks on the bearing surface of the rim or tread commonly known as chill cracks. The cavity in the mold forming the bead serves as agate for obtaining ...a proper distribution of the metal from the heads to all the bracket-s and all parts of the plate section and the inner part of the rim and the outer part of the hb, and in the finished wheel the bead formed in the bead cavitymaterially strengthens the wheel. The movement of the vmetal from the risers to the rim and hub in the manner described is facilitated by the gradual enlargement of the sectional area of the mold cavity from the rim' cavity inwardly toward the risers and from the hub cavity outwardly toward the risers, this being secured by enlarging` the plate from the hub and rim toward the risers, as shown in Figs. i and 3, enlarging i the outer brackets inwardly, enlarging the inner brackets outwardly, enlarging the in? Figs 2 and l, and by the cavities forming the swells 6a, 7*l and 8a on the brackets, thereby allowing proper contraction of the rim section in its congealed state and avoiding the defective deformation of vertical chill cracks in the face of the tread.- .This enlargement of the plate brackets also tends to slow up the setting of the metal contained therein which allows the circumferential and radial shrinkage and contraction of the previously congealed tread section to take place without producing defects known as chill cracks.l

The objects of this increased sectional area ofthe plate and bracket are thus attained, one to properly assist in feeding the molten metal to the plate and bracketv sections adjacent to the rim, and the other to keep this sectional area-molten so that the rim section can properly contract.

The chilling of the tread increases the density .of the metal therein as well as the hardness thereof. rl`he chilling of the hub with` lighter chiller only increases the density of the metal in the same because in the proper formation the hub should be soft and strong. ln the manufacture of a wheel ofl this kind,

a h igh carbon metal is preferably employed which will produce steel too hard for easy l machining. The use of an innerfhub lining o r'chlllmade of soft steel is therefore desirable 1n order tofacilitate the boring or machining of the hub so that the wheel may be Iproperly fitted on its axle. A secondary object of the chill lining in the hub is to increase the density of metal in the hub, not its hardness, thereby avoidingthe use of heavy gates'or risers, because it will tend to cool th1s heavy section of metal quickly and thereby make a uniform and dense casting of the hub. l

lt will be apparent from the foregoing that a car wheel made in accordance with .my invention will be practically free from any defects due to shrinkage strains or other improper formation or conditions which are present in wheels made in accordance with the method heretofore commonly practised. My improved. wheel is therefore much stronger-and safer and these advantages are' secured in addition .to a material decrease in cost of the same.

I claim as my invention:

1. The hereindescribed method of making car wheels consisting iin pouring the bearing face of the rim against a chill of metal and pouring the hub against a lining of relatively soft metal.

2. 'lhe hereindescribed method of making the weight of the wheel and therefore in the car wheels consisting in pouring the bearing Y face of the .rim against a chill of metal and pouring the hub against a lining of relatively the rim and hub are cast and so constructing themold that its sectional area gradually increases from said rim and hub portions of thev cavity toward said risers.

4. The hereindescribed method of making integral cast metal car wheels having a hub, a rim, a plate connecting the hub and rim and having a depressed inner part and an elevated outer part, inner brackets connectin the depressed part of the plate andthe hui,` and outer brackets connecting the ele- Vated part of the plate and the rim, consisting in first casting the hub, inner brackets and depressed part of the plate and`y then casting the outer elevated part of the plate, the outer brackets and the rim during a uni-v form curing of the molten metal.

5. he hereindescribed method of making an integral cast metal car wheel which consists in first casting the `entire hub and inner part of the supporting body and immediately masas thereafter casting the outer part of the sup porting body and the rim of the wheel.

6. The hereindescribed method of making integral cast metal car wheels having a hub, a rim, a plate connecting the hub and rim, inner brackets connecting the inner part of the plate and hub and outer brackets connecting the outer part of the plate and the rim, consisting in first casting the hub7 inner brackets and inner part of the plate followed immediately thereafter by the casting of the outer brackets, outer part of the plate and the rim.

7. rIhe hereindescribed method of making cast metal car wheels having a hub, a rim, a plate connecting the hub and rim, inner brackets connecting the inner part of the plate and hub and outer brackets connecting the outer part of the plate and the rim, consisting in first casting the hub, inner brackets and inner part of the plate followed immediately thereafter by the casting of the outer brackets, outer part of the plate and the rim during an uninterrupted and uniform pouring of the metal into the mold.

8. rlhe hereindescribed method of making integral cast metal car wheels having a hub, a rim, anda supporting body connecting the hub and rim, consisting in first casting the entire hub and inner -part o'f the supportingA body and then casting the outer part of the supporting body and the rim.

CLIFTON W. SHERMAN.

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