US1527338A - Centrifugal pipe mold - Google Patents

Description

Feb. 24, 1925.

c. E. W ILDER CENTRIFUGAL'PIPE MOLD Filed Oct. 2.5, 1923 2 SheetsPSheet 1 VAk Feb. 24, 1925. c. E. WILDER CENTRIFUGAL PIPE HULD Filed Oct. 25, 1925 2 Sheets-Sheet? Patented Feb. 24, 1925.

UNITED STATES PATENT OFFICE.

crimson n. wnamn, or mvnm, rnnnsnvanm.

CENTBIFUGAL PIPE HOLD.

Application filed octol er as, 192:. Serial Ira-erases.

To all whom it may concern:

Be it known that I, CLINTON E. Wrronn,

a citizen of the United States, residing at Irvine, in the county of Warren and State of Pennsylvania, have invented certain new and useful Improvements in Centrifugal- Pipe Molds; and I do hereby, declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the artto'wliich it appertains to make and use the same, reference being had to the accompanying drawings, and to'the letters of reference marked thereon, forming part of this specification.

This invention relates to improvements in the construction of mold tubes for centrifugal casting machines, in which machines the mold tube is rotated at a high rate of speed while a stream of molten metal is introduced therein in asuitable manner. v

Herctofore it has been the practice to construct the mold tubes for centrifugal casting machines of suflicient wall thickness to ensure the mold tube retaining accurate align- .ment which necessitatespa wall substantiallyone and one-half inches thick. This mold tube is placed in an enclosing-jacket spaced therefrom, and mounted in suitable bearings,

and provided with mechanism adapted t9 cause the mold tube to rotate rapidly within said jacket, and there is provided a means to. circulate water in the space between said acket and mold tube to keep the mold tube which has been cooled sufliciently to shrink V cool, as shown in U. S. patent to De Lavaud No. 1,398,008.

I have found from practice that with the thick walled mold tube considerable time is required for the thick wall of mold tube to cool, after being heated by the moltenmetal, owing to the resistance of the thick, heated, mold tubeto the'transference of cold from the water jacket to the layer of hot metal loose from the mold tube and be withdrawn therefrom.

come the difliculties incident to'the use of a thick walled mold tubein a casting machine. I overcome these difiiculties by providing a comparatively thin,-say one half of aning radially therefrom "studs adapted to en- 1 gage the interior surface of said thick walled mold tube to support said thin walled liner, and between said elastic metal bands the space between the liner and the thick mold est diameter, and flows therefrom backintofsaid jacket through holesin the wall of the thick mold tube at its greatest diameter, thus causing a continuously .moderate longitudinal circulation of cooling fluid through the space between said tubes without causing the liner to become checked or otherwise injured, the cooling medium in the space becoming sufficiently heated to prevent injury to the cast metal, and yet preventing the thin liner from becoming injured. The thin wall: of the liner presents so little-resistance to the transference of cold from the cooling medi, um to the cast metal, that it is quickly cooled sufficiently to be removed from the liner.

These and. other features of this invention will be hereinafter set forth and pointed out, and are illustrated in the accompanying drawings in which:

Figure 1 is a longitudinal section of a mold tube and'liner therein, according to my invention. I

" Figure 2 is a transverse section thereof on the line 22- in Fig. 1. w

Figure 3 is a transverse section of the same on the line 3-3 inFig. 1.

Figure tie a transvers'e'section of the sam on the line 4+4 in Fig. 1 1

In these drawings A indicates the ordinary thick mold tube as ordinarily used 4 4 a centrifugal casting machine, and as or- The object of this invention is to over-' dinarily used in a machine of the De Lavaud its interior, while in this invention the thick tube- A serves only to support, in true alignment, the comparatively thin lining tube B,-

-which in reality is. the mold tube of the structure.

'- The thick mold tube A. is provided with series of holes a at the small diameter of the tube, as at- .the cross-seetionlal- (see Fig. 4) Said holes are at an angl through the wall of the mold tube A, so that when the tube revolves in the direction of the arrow in Fig. 4, they tend to scoop in water from the water jacket, (not shown) of the machine, in which the tuber-evolves. There are preferably several'series of these holes a along the length of the tube, while at the largest diameter of the mold tube A is a series of holes a at the cross section line 2-2 in Fig. 1, see Fig. 2, which are inclined backward from the direction of revolution of the tube A so that they will not scoop in water from the water jacket (not shown) and being at a greater diameter tend to throw the water out of the holes a and thus tube A, so as to allow.for the expansion of the tube B during the pouring of the molten metal thereinto. Thus it will be seen that the thin lining tube B. will be perfectly supported by the thick outside tube A,

' and prevented from becoming out of alignheat;

ment. I

The space between the tubes A and B between t e elastic metallic rings C is filled with'coiled wire D, the several coils D being interlaced as shown in Figs, 2 and 4,

so that they will form a band of coiled wire around the tube B between the rings C. The diameter of the coils D is equal to the width of the space between the tube A and the tube B.

Into the several coils D I place material capable of absorbing water and resisting I have found that asbestos rope is well adapted for this purpose. This asbestos material fills the interior of the wire coils, but leaves spaces (1 between the wire coils on the walls of the tubes A and B, andbe; tween the coils D through which water can circulate longitudinally of the tube A. These wire coils D, thus filled with a porous material D acts to keep the thin tube'B in alignment between the rings C, and serves to retard the longitudinal flow of water through the space between said tubes. so that the water becomes sufiiciently hot enough to prevent over chilling of the-casting, and at the same time prevents injuring the tube B. The difference in temperature between the water in the space between the tubes A. and-B will be readily transferred through the thin tube B to the layer of hot metal thereon to cause it to cool sufficiently to shrink away from the mold tube B so that it can easily be withdrawn therefrom.

The outer tube A is provided with an annular shoulder E against which the outturned flange E on the tube B engages, and from 1 the shoulder E screw threads F are provided in the outer tube, which engage threads on a rin G which screw into the end of the tube A and force the flange E securely against the annular shoulder E.

At the opposite end of the tube A is an inturned annular flange H against which the coils -D and rope filler D abut, while the inner tube B extends through the flange H and through a gland-ring H which presses against suitable packing in to seal the joint between the tube B and flange H. Secured to the outer tube A are tap bolts J upon which a ring K is placed which is adapted to engage'the end of the tube B. and on the tap bolts springs J and nuts J 2 are placed so that the springs J press against and force the ring K against the tube B with a yielding pressure so as to compensate for the longitudinal expansion of the inner tube B. 1

In use, this outer tube A and lining tube B are inserted into a molding machine of the type shown and described in U. S.

Patent No. 1,398,008, hereinbefore-referred to, in the usual manner and the water jacket therein filled with water in the usual manner, so that when the mold tubes herein des'cfibed are rotated, water from the water jacket enters into the space between the outer thick tube A and the inner liner tube B' through the holes a in the wall of the tube A and saturates the asbestos filler in the coiled wire centering supports D, and is caused toqlongitudinally circulate thereabout and therethrough by reason of the difierence in diameter of the tube A where the intake holes a and the outlet holes a pierce the wall of said tube, so that the outside of the thin mold tube B is at all times surrounded by a hot moist layer of heat proof material with sufficient circulation to carry off the burning heat of the molten metal, and thereby prevent the' burning'of the tube B, so that the same will not become checked on its inner surface, and will not become sufliciently chilled to injure the surface of the cast metal. The thin wall of the tube B, offers little, if any. resistance to the transference of heat from the cast' metal to circulating cooling water inthe space between the two tubes A and B, and which is carried ofi thereby. 7

As the pouring spout recedes, and the molten metal is laid upon the inner surface of the rotating mold tube B, always upon a portion which has been cooled by the slowlycirculating cooling fluid, said.

fluidbecoming thereby heated as it travels forward over that portion of the mold tube upon which the hot metal has been deposited, so that while the incoming cooling fluid nmintains the succeeding portion of the mold tube in a cool condition to receive the metal deposited thereon, the cooling water at the point receiving the hot metal becoming sufficiently heated to cause the molten metal to cool slowly so as not to.

duced, so that the initial diameter of the cast metal is correspondingly reduced, so that the contraction of the cast metal as it hardens .is relatively greater than the contraction of the tube B, so that an air space progressively forms between the cast metal and the tube B, which space progresses longitudinally until the casting is' finished.

During this progressive casting operation the cooling medium between the tubes A and B becomes heated sufliciently to prevent the contraction of the tube B, but still retains a sufficient difference in temperature to carry oil the heat from the cast metal to cause the required amount of contraction to enable it to be easily withdrawn from the mold tube.

Because the mold tube B, being comparatively thin, is easily kept cool the machine casting toshrink sufliciently to be withdralwn, or for an overheated'mo-ld tube to coo Having thus described my improved molding tube for I centrifugal casting machines, so that others will be able to utilize the same, I do not desireto be limited to the exact construction thereof herein shown and described, as it is evident that-many modifications can *be made therein without departing from thescope of my invention,v

therefore what I claim as new and desire to secure by Letters Patent is:

-1. A mold tube having a comparatively thin wall, another tube having a thick wall enclosing said mold tube and spaced therefrom, elastic means surrounding said mold tube and contacting with the inner surface of said thick' outer tube and adapted to maintain all portions of said mold tube concentriowith the inner wall of said thick;

outer'tube, and means to 'causea longitudinal circulation-of water between said from, elastic'means surrounding said moldtube and contacting with the inner surface of said thick outer tube, and adapted to maintain all portions of said mold tube concentric with the inner wall of said thickouter tube, and means to cause a longitudinal circulation o-f water between said tubes, asbestos material filling between elastic means to retard said circulation.

3. In a mold tube having a comparatively thin wall, another tube having a comparatively thick wall enclosing said mold tube and spaced therefrom, a series of corrugated metallic rings surrounding said mold tube, spaced at intervals, radial studs formed on said rings and adapted to engage the inner surface of said outer tube, means to cause a tively thick wall enclosing said mold tube and spaced therefrom, longitudinally interlaced coiled wires engaging the outer sur face of the thin mold tube and the inner surface of the thick outer tube and adapted to ma intain ,themold tube longitudinally concentric with said outer tube, asbestos material extending through each of said wire coils, and means to cause water to longitudinally circulate through the annular space between said tubes.

5. In a. moldtube having a comparatively thin wall, another tube having a compara- .tively thick wall enclosingsaid thin tube, does not have to standidle to permit the a means to cause water to longitudinally circulate through the annular space between said tubes, -and means to retard said circulation. I

, 6; Ina mold apparatus, an inner mold tube having a thin wall, an outer tube enclosing said mold tube and adapted to support the same,- metallic rings placed at intervals on said innertube and adapted to engage the inner surface of said outer tube to concentrically support said mold tube within said outer tube, inte-rlaced coiled wire around said mold tube between said corrugated rings of a diameterto engage the outer surface of the mold-tube and the inner surface of the thick "outer tube adapted-to concentrically support said,mold"t1 1be within said outera plurality of corrugated tube between-said corrugated metallic rings,

and asbestos ropes inserted longitudinally through said interlaced wire coils.

In testimony whereof I aflix my signature.

cnmron E, WILDER.

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