US3369555A

US3369555A - Apparatus for heat treating annular castings

Info

Publication number: US3369555A
Application number: US504844A
Authority: US
Inventors: Jr William M Heflin
Original assignee: Amsted Industries Inc
Current assignee: Amsted Industries Inc
Priority date: 1963-05-03
Filing date: 1965-10-24
Publication date: 1968-02-20
Anticipated expiration: 1985-02-20

Description

Feb. 20, 1968 w. M. HEFLlN, JR 3,369,555

APPARATUS FOR HEAT TREATING ANNULAR CASTINGS 2 Sheets-Sheet 1 Original Filed May 5, 1963 INVENTOR Qm Qm Feb. 20, 1968 w. M. HEFLIN, JR 3,369,555

APPARATUS FOR HEAT TREATING ANNULAR CASTINGS ab. iii

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Original Filed May 5, 1963 al ows WM United States Patent 3,369,555 AliARATUS FOR HEAT TREATING ANNULAR CASTINGS William M. Heliin, .Ir., Elmhurst, Ill., assignor to Anisted Industries Incorporated, Chicago, Ill, a corporation of New Jersey Original application May 3, 1963, Ser. No. 277,756, now Patent No. 3,242,017, dated Mar. 22, 1966. Divided and this application Get. 24, 1965, Ser. No. 504,844

1 Claim. (Cl. 134123) ABSTRACT OF THE DISCLOSURE A table 42 rotatable on a substantially vertical axis comprises guide members 46 and 48 having substantially parallel mutually facing

guide surfaces

56 and 52 for clamps or jaws 62 and 64. The jaws comprise right-hand and left-hand threaded nuts 66 and 58 engaging complementary threads of a screw 56 for actuation thereby to clamp one end of a railway car wheel hub 122 whereby the table and wheel may be rotated so that its rim 126 is sprayed by a coolant fluid from nozzles 94 mounted on a manifold 92 carried by legs 96 maintained by bolt and nut assemblies 100 within slots 162 of frame members 90 whereby the manifold 92 and its nozzles may be adjusted in a plane substantially parallel to the rotational axis of the screw 69. This arrangement not only accommodates wheels of various sizes and dimensions, but also permits adjustment of the spray nozzles 94 to compensate for misalignment of the Wheel in the event the distance between the rim and the nozzles at one side of the clamped wheel should be less than that between the rim and the nozzles at the opposite side of the wheel.

This application is a division of my copending application Ser. No. 277,756 filed May 3, 1963, now Patent No. 3,242,017, granted Mar 22, 1966.

This invention relates generally to the production of annular ferrous castings, such as cast teel wheels, and more particularly to a novel apparatus for heat treating such castings in order to obtain increased hardness and ductility in selected portions of such castings.

In the production of cast steel railway wheels, it has been common practice to normalize the wheels by heating them above the critical temperature range of the metal (approximately l,260 to 1,350 F.) and then allowing them to cool in air. Normalizing of such cast steel wheels was performed in order to enhance certain physical characteristics, such as resistance to impact and abrasion.

However, the normalizing of cast steel wheels has not proven to be entirely satisfactory. Various factors, that are controlled only with difficulty, influence the results obtained through normalizing. For example, in order to achieve maximum benefits of normalizing and avoid the creation of undesirable residual stresses, all portions of the cast steel wheel should be cooled through the critical temperature range at approximately the same rate in order to have substantially uniform rates of contraction in all portions of the wheel.

Air cooling of wheels, as is required in the conventional normalizing process, is not entirely compatible with the above requirements because of the great variations in metal thickness as between the wheel rim, plate and hub.

Accordingly, it is an object of this invention to provide a novel apparatus for heat treating cast steel wheels so as to achieve greater hardness and ductility than that previously attainable.

3,369,555 Patented Feb. 20, 1968 Another object of this invention is to provide a novel apparatus for heat treating cast steel wheels so as to obtain increased hardness and ductility in selected portions of cast steel wheels.

Other objects and advantages will become apparent When reference is made to the following written description taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a fragmentary top plan view of a spraying arrangement for carrying out the teachings of this invention;

PEG URE 2 is a cross-sectional view taken substantially On the plane of line 22 of FIGURE 1 and looking in the direction of the arrows;

FIGURE 3 is a fragmentary partially sectioned view taken substantially on the plane of line 33 of FIGURE 2 and looking in the direction of the arrows; and

FIGURE 4 is a cross-sectional view illustrating a suitable spraying assembly for carrying out the teachings of this invention.

Certain details are omitted from one or more figures for purposes of clarity.

Referring now in greater detail to the drawings, FIG- URES 1 and 2 illustrate an arrangement for toughening wheel rim comprised of a base 10 supporting a water collecting tank assembly 12, turntable assembly 14 and a sprayer assembly 16.

Base 16 may be comprised of a plurality of vertically extending legs 18 the upper ends of which are connected to each other by an annular capping member 20 secured thereto as by welding. Supporting arms 22 and braces 24 are provided intermediately of legs 18 for upporting a lower bearing mounting block 26 adapted to receive a suitable bearing 28 therein. 7

A pair of laterally extending support members 3%, each secured at their ends to the annular capping member 20, are provided for supporting an upper bearing mounting block 32 which is adapted to receive a suitable bearing 34 therein.

A vertically extending drive shaft 49, journalled within bearings 28 and 34, and provided with a shoulder portion 36 to prevent downward movement thereof, is connected by any suitable means, such as a key 38, to the turntable assembly 14.

The turntable assembly 14 is comprised of a generally rectangular table or support 42 having formed thereon a downwardly depending portion 44 with provisions for closely receiving the upper end of said drive shaft 40 therein. Table 42 is provided with longitudinally extending guide members 46 and 48 having their respective

inner guide surfaces

50 and 52, respectively, substantially parallel to each other.

A journal member 54, such as a conventional pillow block, secured to table 42 receives an adjusting screw 56 having right and left-hand threaded portions 58 and 6%, respectively. Clamping blocks or jaws 62 and 64, each partially received between

guide surfaces

50 and 52, are provided with internally threaded portions as by securing thereto right and light-hand threaded nuts 66 and 68, respectively, which threadably receive the adjusting screw 56.

Preferably, each end of adjusting screw 56 is provided with a driving slot 70 whereby screw 56 may be rotated to move clamping blocks 62, 64 either toward or away from each other.

The water collecting tank 12 may be comprised of a generally cylindrical vertically extending wall 72 to which is secured, at its lower end, an annular bottom plate 74.

A second continuous wall 76 extends vertically upwardly from an inner opening 78, appropriately formed in plate 74 to closely receive legs 18 therethrough. Preferably, wall'76 is extended sufliciently upwardly so as to abut against the lower edge of capping member 20. All joints of the watertank should of course be made water tight. A'radially extending annular cover plate 80 is placed about block 32 and atop both capping member 20 and transversely extending supports 30.

A plurality of mounting brackets 82 are secured to the interior of wall 72. Supporting arm assemblies 84, comprised of

end plates

86 and 88 securing together oppositely disposed lengths of angle iron 90, are, inturn, connected between capping member 20 and mounting brackets 82.

Sprayer assembly 16, comprised of an annularly formed conduit 92 serving as a manifold for a plurality of nozzle assemblies 94 connected thereto, is preferably supported by four rod members 96 slidably received with adjustable rod support members 98. Each of the rod support memhers is retained between the lengths of angle iron frame members 90 and adjustably secured thereto by means of oppositely disposed radially extending threaded rod portions 100 received through slots 102 formed in angle iron frame member 90. Nozzles 94 are preferably of the adjustable type, having possibly a swivel-like joint, permitting the adjustment of each nozzle so as to obtain the desired angle of discharge therefrom. In the preferred form of the invention, as illustrated, sixteen nozzle assemblies would be substantially equally spaced about manifold 92.

A supply conduit 104, having a valve 106 serially connected therein, communicates between a source 1080f cooling fluid and manifold 92. Bottom plate 74 may also be provided with an orifice 109 through which the spent cooling fluid can drain to a suitable vessel.

A conventional flexible coupling 110, right angle speed reducer 112, fluid coupling 114 and a prime mover 116 maybe employed in an arrangement as shown for rotating drive shaft 40.

OPERATION The operation of the invention is briefly as follows. The annular casting, in this case cast steel railway wheel 118 is preferably heated to a temperature of approximately 1,550 to 1,600 F. and placed upon the turntable assembly 14. Clamping screw 56 is turned causing jaws 120 of clamping blocks 62 and 64 to move against the outer diameter of the wheel hub portion 122.

Prime mover 116 is then activated thereby rotating shaft 40 causing the turntable assembly 14 and wheel 118 to be rotated about centerline 124. Valve 106 is opened allowing source 108 to force a suitable cooling fluid, such as water, through conduit 104, manifold 92 and nozzles 94 against rim portion 126 of wheel 118 in a spray as generally illustrated at 128. I

Wheel 118 is continually rotated and spray 128 applied thereto until the temperature of the wheel is brought to below the critical temperature range. Preferably, the water spray is continued until the wheel is at a temperature of between approximately 400-700 F. The increased cooling resulting from the water spray causes the rim tread to have a very fine pearlitic structure with both increased hardness and ductility as compared to the air cooled wheels of the prior art.

As was previously mentioned, care must be taken to cool both the thick and thin sections of the wheel at approximately the same rate through the critical temperature range. This is much more easily accomplished by the use of the invention. The continual rotation of wheel 118, at relatively high speeds, prevents the water spray impinging upon rim 126 from progressing inwardly upon plate 130 towards the hub portion 122. That is, all the spent cooling fluid is thrown off rim 126 in an outward direction.

Astill further benefical effect is obtained from the rotation of wheel 118. As between any two radially spaced points on wheel 118, the point closer to the axis of wheel 118, has a linear velocity less than that of the point further away. This is true even though the angular velocity of wheel 118 remains constant. The linear velocity of any point on the wheel is proportional to its distance from the axis of rotation. Accordingly, since the static pressure of a fluid is, among other things, dependent on its relative velocity (the higher the .velocity, the lower the static pressure) it can be seen that the static air pressure nearer the hub diameter is greater than that nearer the rim portion.

Therefore, a pumping action is created by wheel-118 which results in a flow of air over hub 122 and plate having a pattern illustrated generally by the heavily shaded arrows 132. Likewise, the bore 136 has an air flow pattern therein illustrated by arrows 134.

The air flows, as described above, aid in the removal of heat from both the plate 130 and hub 122. .That is, the rate of heat dissipation is greater than would otherwise be obtained ina relatively stagnant ambient atmosphere.

After the wheel has cooled to a temperature of between 400 to 700 F., as described, it is then removed from the turntable assembly 14 and reheated to a temperature of approximately 900 F. in order to temper the castings and remove undesirable stress therefrom. Re heating of the wheel, of course, does not in any way adversely effect the microstructure of wheel tread surface as created by the water spray.

The wheel, after being reheated to approximately 900 F, is then placed on a suitable supporting structure 138 (FIGURE 4). A bore spraying nozzle assembly 140 is then introduced into bore 136 as illustrated. The nozzle assembly 140 is preferably comprised of a generally circular flange 142 secured to a vertically depending manifold 144 having formed therein a conduit 146 which communicates with a plurality of axially spaced radially directed spray nozzles 148. Conduit 150, having a valve 152 serially connected therein, communicating with a suitable source- 154 of cooling fluid, in this case water, serves to convey the cooling fluid to conduit 146 and subsequently to nozzles 148.

After the reheated wheel is placed on support 138 and nozzle assembly 140 inserted therein, valve 152 is opened permitting source 154 to force cooling water through spray nozzles 148 against the hub bore 136. Preferably, the spray of water is continued until the temperature of the wheel is again reduced to 400 to 700 F. The final water spraying of the hub serves to create favorable internal stresses within the wheel. That is, when the wheel is finally completely cooled, the plate portion'130 is placed in both including spaced guide members with substantially paral-' lel mutually facing surfaces, a pair of spaced jaws having portions slidea'bly engaging the guide surfaces, said jaws having, respectively, right-hand and left-hand threads,

screw means having a rotational axis and having right hand threads and left-hand threads engaged with corresponding threads of respective jaws, one end of said hub being seated on top of said guide members, actuating means for rotating said screw means on said axis to clamp said jaws against said one end of the hub, a spray manifold encircling said rim and spaced therefrom, said manifold having a plurality of spaced nozzle means for directing coolant fluid against the rim, and means for adjusting the manifold in a path parallel to the rotational axis of said screw means for positioning the nozzles substantially equidistantly from said rim when clamped by said jaws, and means for rotating the supporton an axis 5 perpendicular to the first mentioned axis to rotate the wheel rim through the coolant fluid when the hub is clamped by the jaws.

References Cited UNITED STATES PATENTS 6/1926 Schwaner 134-449 1/1929 Kenney 134-123 XR 6 2,081,142 5/1937 Branaman 134-149 2,240,493 5/1941 Denneen 134123 3,043,317 7/1962 Hursen 13445 5 CHARLES A. WILLMUTH, Primary Examiner.

ROBERT L. BLEUTGE, Examiner.