US1777979A - Method of and flask for facilitating solidification of metal centrifugally cast against a refractory lining - Google Patents

Description

A. LOSEY METHOD OF AND F K FOR FA ITATING SOLIDIFICATION OF METAL I CENTR INS REFRACTORY LINING IFU LY CAST Filed March Wifnesses: 2 -//71/em0r.-.

Patented &17, 1930 UNITED STATES PATENT OFFICE ARTHUR LosEY, or BAY snonn, NEW YORK, ASSIGNOR TO SAND SPUN PATENTS coa- IORATION, OF NEW YORK, N. Y.,

METHOD or an]:

A CORPORATION OF DELAWARE FLA-SK For. rncrmrn'rrne soninrrrcarron or METAL CENTRE- UGALLY cns'r AGAINST A nnrnacromr LINING Application filed March 4, 1927. Serial No. 172,669.

This invention relates to improvements in method of and flask for facilitating solidification of metal centrifugally cast against a refractory lining.

The principal object of my invention isto facilitate solidification of metal from a fused state into a useful solid form and conserve heat now' dissipatedwhen metal pipe and other articles are centrifugally cast, without bringing about abnormal stresses of the metal during solidification, thereby making it possible to manufacture centrifugally cast products of superior quality in refractory lined moulds more efliciently than by methods now in use. v

With the above and other objects in view, the present invention broadly considered, provides certain novel features such as will expedite the moulding, casting and extracting operations, as follows:

In the manufacture of centrifugallycast pipe by the usual method in which a rotary metal flask with a refractory sand lining is employed, both sensible heat and the latent heat of-fusion of the metal are absorbed by the refractory sand lining during the casting operation and is rejected as each hot sand lining surrounding the hot pipe is removed, whereas; by my method,--the heat is permitted to pass through a minimum thickness of refractory sand lining and is conducted and absorbed at a much higher rate by a siliconcarbide lining which is provided within an outer flask member, whereby a minimum quantity of heat is rejected as the thin sand hning is removed, while the heat absorbed by the silicon-carbide lining which. remains within the rotary'fla'sk member is conserved and this absorbed heat is utilizedto evaporate moisture froma subsequently rammed moist sand lining preparatory to a centrifugal casting period.

Another novel feature of my invention resides in the provision of a method of arranging and using a silicon-carbide lining within a rotary flask member adapted torreceive an inner sand lining, constructed in such manher as will, facilitate the solidification of metal centrifugally cast against said inner sand lining;

o Another novel feature of my invention re sides 1n the provision of a method of arranging and using a silicon-carbide inner core, about which is formed a baked sand bell-core which is inserted at hell end of the flask, for facilitating solidification of the otherwise slow cooling, thick bell end of centrifugally cast pipe.

Still another novel feature of iny invention resides in the provision of a certain method of arrangement and use of prepared materials more fully illustrated in the drawing, described in the specification and set forth in the'claims.

My invention is illustratedin the accompanying drawing, in which Fig. 1 is 'a longitudinal section through a rotary mould containing a centrifugally cast pipe, in accordance with my invention.

Fig. 2- is an enlarged transverse section through said mould and pipe 'on line 2-2 of Fig. 1-.

Like numerals refer to like parts throughout the views.

It should be understood that the drawing is suggestive and the invention may-be embodied in various forms other than the one shown. 4

A preferred form of flask constructed in accordance with my invention is as follows:

An outer flask member 3 is provided with hand rails 4 which permit rotation of the assembled flask on its longitudinal axis when mounted upon rollers of a centrifugal casting machine. The bell end of the outer flask member is enlarged at hub 5 to receive a silicon-carbide heat absorbing flask hub lining 6; Inserted in the barrel of said outer flask member are a'plurality of silicon-carbide heat absorbing lining units .7 which are provided with ,vent perforations 8 and annular vent-grooves 9. .T he annular vent grooves register with vent perforations 10 which are locked by lock nuts 14. Four adjusting screws 11 for each respective alternateunit serve to force said unit against the opposite side of the outer flask member; likewise four adjusting screws 12 for each of the remaining alternate units serve to force each respective alternate unit against the opposite side of the outer flask member. A bell-core centering flange 15 is attached to the bell end of the outer flask member by key bolts 16 and wedge keys 17. The spigot end of the outer flask member is enlarged at hub 18 to receive a silicon-carbide heat absorbing spigot ring 19. .A pattern centering flange 20 is attached to the spigot end of the outer flask member by key bolts 21 and wedge keys 22. f

A heat absorbing flask having been prepared as above described, a moist sand lining 23 is rammed around a pattern which is centered at the spigot end by the pattern centering flange'and at the bell end by the bell-core centering flange. After removing the pattern any suitable facing maybe ap-' plied tothe moist sand lining. A belLcore 24 having been formed around a silicon-'carh bide heat absorbing inner core 25 securely engaged by a core retaining ring 26 is inv serted into the bell-core centering flange and secured by wedge keys 27. A Venturi flue 28 formed through'the axis of the silicon-carbide inner core facilitates the acceleration of gases during the casting operation. A baked sand stop ring 29 is inserted-into the silicon-carbide heat absorbing spigotring and is held in -j place against the refractory sand lining by a stop bushing 30.

The prepared mould may then be delivered to a centrifugal casting machine where molten metal is poured into'the rotating mould. After solidification has been facilitatedb the silicon-carbide heat absorbingflask hub hning, inner core, ring, the mould may be removed from the casting machine, and the sand lining and the centrifugally cast pipe 31 may be removed without removal of the silicon-carbide heat absorbing lining from the outer flaskmember. Another rammed moist sand lining may be formed within the flask and heat absorbed by the silicon-carbide heat absorbing hmng may be employed to evaporate moisture from the moist sand lining preparatory to a repeated casting operation.' 4 Various constructions may beemployed other than thatshown in the drawing and .although I have described a construction and operation relating to the manufacture of.

pipe, it is not intended as a limitation of my invention'which may be used in the manulining units and spigot carbide, and a rammed lining of molding sand, said lining covering each part of the mold with which the molten metal contacts during the casting.

'2. A hollow mold for centrifugal casting,

4. A hollow mold for centrifugal casting,

comprising a flask, alining for the flask of] molded silicon carbide, and a rammed facing for the lining of molding sand, the silicon carbidev casting having radial vents and ex? ternal-annular grooves with which the vents communicate.

5. A head or bell end core for centrifugal casting, including an inner core or body of silicon carbide, and aiming of moldingsand to contact with the molten metal molded onto the body.

. 6. A head or hell end core for centrifugal J casting, including an inner core or body of silicon carbide, and a facing of molding sand flowing from the bell end of the mould .to' contact with the molten metal molded onto the body, said inner core or body having an axial opening for the purpose specified.

7. Mechanism forcasting hollow bodies centrifugally, consisting ofa mold composed of a body of silicon carbide'and a molded name to this specification this second .day

of March, 1927.

' ARTHUR LOSEY.

facture of various cast products, and what i I claim asbeing new and desire to secure by LettersPatent is:

1. A mold for thecentrifugal casting of hollow bodies,

composed of molded silicon

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