US1850743A

US1850743A - Method of casting products embodying material of low specific gravity

Info

Publication number: US1850743A
Application number: US525128A
Authority: US
Inventors: Donald S Connelly; Theodore J Hahn
Original assignee: Wooster Products Inc
Current assignee: Wooster Products Inc
Priority date: 1931-03-25
Filing date: 1931-03-25
Publication date: 1932-03-22
Anticipated expiration: 1949-03-22

Description

March 22, 19 2- D. s. CONNEILLY ET AL 1,850,743

METHOD OF CASTING PRODUCTS EMBODYING MATERIAL OF LOW SPECIFIC GRAVITY Filed March 25. 1931 Jwuantow p. a comgzg Z J Hal/212 Patented Mar. 22, 1932 UNITED STATES PATENT OFFICE DONALD S. GONNELLY, OF WOOSTEB, AND THEODORE I. HA ER, OF CARTON, OHIO, .AS-

SIGNOBS 1'0 WOOB'I'ER PRODUCTS INC, 01' WOOSTEB, OHIO, A CORPORATION OF OHIO METHOD OF CASTING .ZPBODUCTS monme LOW SPECIFIC GRAVITY Application mm ma a5, 1931. semi 110. 525,128.

The invention relates to a method of producing' cast bodies bodily incorporating zones of relatively low specific gravity material.

5 More particularly, the invention relates to a method of producing cast metal stair treads, embodying segregations of comminuted abrasive or wear-resistant material.

Stair treads which are in common use are usually provided with a coating or wearing surface of abrasive or wear-resistant material. A common method of producing such stair treads is to sprinkle the surface of the mold in which the tread is to be cast with comminuted resistant material, spray the resistant material with a suitable binder, and then pour the casting.

Stair treads produced by this method however, present a wear-resistant coating, the

particles of which are rapidly dislodged or =worn 0E in use, and the more or less pure cast metal next encountered does not possess the necessary frictional and wear-resistant qualities.

Itis therefore desirable to provide a cast stair tread containing comminuted wear-resistant material distributed throughout the same, but a satisfactory method of making the same has not, to our knowledge. been that when the molten metal is poured into the mold, wear-resistant material which is free to move, will rise to the top of the mold because of its relatively low specific gravity.

Accordingly, it is an object of the present invention to provide a method of producing a casting having comminuted abrasive or wear-resistant material substantially segregated at desired zones in the casting.

Another object is to provide for substantially restricting the flow of and segregating the comminuted material during the casting operation, by employing a medium of such character that the same will become substantially fused and merged with the cast metal when the latter has become chilled.

, A- still further object is to provide a method of producing a casting having commi- 50 nuted abrasive or wear-resistant material known in the past. The difiiculty arises in' lsrlplstantially distributed throughout the cast These and other objects are attained by the improved method comprisin the present invention, as will be hereina er pointed out in detail. 7

In general terms, the invention consists in sp abrasive or wear-resistant material over the bottom surface of the mold cavity in which the product is to be cast, spraying said abrasive material with a suitable binder, suspending a preferably perforated plate adhesively coated with abrasive or wear-resistant material in the mold cavity in spaced preferably parallel relation to said bottom surface thereof, anchoring said plate against displacement, and pouring molten metal into the mold cavity.

A. preferred embodiment of the present invention is illustrated in the accompanying drawings, in which Figure 1, is a fragmentary cross sectional view of a mold prior to the casting of the product therein, showing a plate coated with abrasiveior wear-resistant material suspended in the mold cavity;

Fig. 2 is a detached fragmentary tive view of the plate partially coated with abrasive on wear-resistant material; and

Fig. 3 is a. fragmentary cross sectional view of the finished product. i

Similar numerals refer to similar parts throughout the drawings.

The invention may be carried out by employing an ordinary mold as shown in Fig.

1, having the cope 10 and the drag 11. The

mold cavity 12 is preferably located in the drag as shown, and has inlet and

outlet gates

13 and 14 respectively, communicating with the ends of the mold cavity.

The cope may be provided with a pouring sprue 15, communicating with the gate 13, and with a riser 16 communicating with the gate 14.

One or more plates, which may be approximately 28 gauge, low carbon steel, are provided for accomplishing segregation of the abrasive or wear-resistant material within the cast product. For convenience, one plate 17 is shown in the drawings.

the body of the This plate is preferably perforated as shown, and adapted to be anchored against displacement in the mold cavity during casting. Before insertion into the mold cavity, however, the plate 17 is thoroughly coated on all surfaces with comminuted abrasive or wear-resistant material asindicated at 18, such as carborundum, which may be applied by using asuitable adhesive, such as asphaltum adhesive material.

The fusing point of the plate 17 is preferably'lower than that of the metal constituting casting, which metal may be cast iron, so that during the casting operation, said plate will become substantially entirely fused and merged with the molten metal.

If desired, a fusible adhesive material, such as sodium silicate, may be used for coating the plate 17 with carborundum, so that when the casting is poured the adhesive will fuse with the molten metal.

The plate 17 may be anchored in the mold cavity immediately adjacent the bottom surface thereof, or suspended and anchored in the cavity in spaced relation to said bottom surface, as shown in Fig. 1. This may be accomplished by any convenient means, as by punching tangs 20 out of the plate for contacting with the cope of the moldto properly space the plate therefrom; and by providing holes 21 in the plate 17, through which foundry nails 22 may be driven into the cope for securing the plate thereto against displacement during the casting operation.

Preferablythe plate 17 is of such dimensions as to have its ends spaced from the ends of the mold cavity, as shown at 23 and 24, when the plate is positioned in the. mold cavity. I

If a plurality of plates 17 are used they may be suspended and anchored in a similar manner at vertically spaced lntervals in the cavity.

Tn carrying out the invention, the mold cavity 12 is formed in the drag 11 in the usual manner. The bottom surface 12- of the cavity 12 is then sprayed with a suitable binder such as asphaltum binder and the like, and comminuted abrasive material, which may be carborundum, is sprinkled over the sprayed bottom surface as indicated at 18. The bottom of the mold cavity covered withthe comminuted carborundum is again sprayed with the asphaltum binder. i

The plate 17 adhesively coated with abrasive or wear-resistant material is then secured to the underside of the cope, in a man' relation to the bottom surface 12 of the ner previously described. The cope is placed in position on the drag, andthe plate 17 is thus suspended in spaced preferably parallel mold cavity, and has its ends spaced from the ends of the mold cavity.

The molten'metal is then poured through and allowed to chill.

When the molten metal enters-the molten cavity through the gate 13, it first flows under the plate '17 and over the bottom of the mold cavity. As the binder holding the abrasive material 18 to the bottom 12 becomes gasified, some of the particles of the abrasive will befreed and begin to rise, due to their relatively low specific gravity.

As the molten metal rises to the region or zone of the adhcsively coated plate 17, its heat will also act upon the adhesive material holding the comminuted abrasive material 18 to the plate, to liberate some of the particles of the abrasive material 18.

Since the plate 17 is secured to the cope against bodily displacement, the pressure of the molten metal upon the underside of the plate 17 would ordinarily tend to warp the plate, but theperforations permit some of the molten metal to be forced up throughthe plate, with the result that any substantial warping of the plate is obviated.

It will be understood that since the metal plate 17 is relatively cold, its effect will be to chillthe molten metal in its immediate zone more quickly than the surrounding metal, with the result that the molten metal becomes pasty and more or less quiescent in the zone of the plate, in a relatively short time. Consequently, the upward flow of a substantial part of the particles ofabrasive material 18 is restricted, since these particles are caught in the zone of pasty metal.

However, a certain proportion of the particles of abrasive material 18 will rise upwardly a substantial distance before the molten metal in the zone of the plate 17 becomes sufficiently pasty to restrict the upward flow of those particles.

Likewise, a certain proportion of the par-v ticles of abrasive material 18 will rise toward the plate 17 but a'substantial portion thereof will be retained at the bottom of the mold cavity until the iron becomes sufliciently pasty to restrict their upward flow. Thus the molten metal becomes intermingled with the abrasive or low specific gravity material.

As aforesaid, the character and thicknes of the plate 17 is such that it becomes substantially entirely fused and merged with the body of the casting by the time the same has become chilled.

The casting 25, shown in cross section Fig. 3, is produced by the improved method using a. single plate 17. The segregated zone 26 of abrasive material at the outer surface of the casting corresponds in location to the bottom surface of the mold cavity, and the segregated zone 27 of abrasive material corresponds to the relative location of the plate 17.

The density of the zone 27 shades off or i the pouring sprue 15 into the mold cavity 12 i material is attained between the segregations thereof.

In use, the zone 26 forms the surface to be presented to wear, and when this surface becomes worn off, the metal next encountered o oifers substantial resistance to wear due to the bodily incorporated distributed particles of abrasive material, although somewhat less wearing resistance than is possessed by the outer skin 26.

lVhen the casting has become further worn off, the zone 27 is encountered which offers relatively high resistance to wear, and the metal beyond that zone still contains suflicient distributed abrasive to ofler substantial and sat- 0 isfactory resistance to Wear.

? 'JVGCl plate coated with wear-resistant matcrial immediately adjacent the bottom surface of the mold cavity before introducing the molten metal.

It is to be understood that various modifications may be made in carrying out the invention, without departing from the scope of the appended claims.

We claim:

l. The method of casting products bodily incorporating wear-resistant material, which includes forming a mold for the product to be cast, suspending a fusible medium adhesively coated with comminuted wear-resistant material in the mold, anchoring said adhesively coated medium against displacement, and introducing molten metal into the mold.

2. The method of casting products bodily incorporating wear-resistant material, which includes forming a mold for the product to be cast, suspending a perforated metallic plateadhesively coated with comminuted wear-resistant material in the mold, anchoring said adhesively coated plate against displacement, and introducing molten metal into the mold.

3. The method of casting products bodily incorporating low specific gravity material, which includes forming a mold for the prodnot to be cast, adhesively coating the bottom of the mold cavity with comminuted low specific gravity material, anchoring a. fusible medium adhesively coated with comminuted low specific gravity material in the mold cavity in spaced relation to the bottom thereof, and introducing molten metal into the mold cavity.

4.- The method of casting products bodily incorporating wear-resistant material, which includes forming a mold for the product to be cast,.adhesively coating thebottom of the mold cavity with comminuted wear-resistant material, suspending a fusible plate adhesively coated with comminuted wear-resistant material in the mold cavity, anchoring said plate against displacement, and introducing molten metal into, the mold cavity.

5. The method of casting products bodily incorporating different materials, which includes coating a fusible medium with comminuted material of relatively low specific gravity, positioning the coated fusible medium in a mold cavity and spaced from the walls thereof, and introducing molten metal into the mold cavity.

6. The method of casting products bodily incorporating different materials, which includes coating a fusible medium with comminuted material of relatively low specific gravity, positioning the coated fusible medium in a mold cavity'and spaced from the walls thereof, and introducing molten metal under the coated fusible medium in the mold cavity.

7. The method of casting products bodily incorporating difierent materials, which includes coating a fusible medium with comminuted material of relatively low specific gravity, placing the coated medium in a mold cavity, and intermingling molten metal with the low specific gravity material in the mold cavity.

In testimony that we claim the above, we

have hereunto subscribed our names.

DONALD S. CONNELLY. THEODORE J. HAHN.