US1934592A - Cast product embodying material of low specific gravity - Google Patents

Description

Nov. 7, 1933. D. s. CONNELLY El AL CAST PRODUCT EMBODYING MATERIAL OF LOW SPECIFIC GRAVITY Original Filed March 25, 1931 UNITED starts PATENT OFFICE V CAST PRoDUcrEMBo YiNG MATERIAL F LOW SPECIFIC GRAVITY Donald S. Connelly, Wooster, and Theodore J. Hahn, Canton, Ohio, assignors to Wooster Products Inc;, Wooster, Ohio, a corporation of Ohio Original application March 25, ios se i i No. 525,128; Divided and this application Becom her 16, 1931. Serial No. 581,354

6 Claims. (01. 20-79) lhe invention relates to cast bodies bodily preferably perforated plate adhesively coated incorporating a zone or zones of segregated relawith abrasive or wear-resistant material in the tivelylow specific gravity material. moldcavity in spaced preferably parallel rela w More particularly, the invetion relates to cast tion to said bottom surface thereof; anchoring metal stair treads embodying segregations of said plate a ainst displacement, and pourin corhminuted abrasive or wear-resistantmaterial, molten metal into the mold cavity; as set forth and this application is a ,division,of our copende in cm I Patent No. 1,850,743.

ing application $erial No. 525,128, filed March In the drawing forming part hereof V 25, 1931, entitled Method of casting products I Figurev 1 is a fragmentary cross sectional view embodying material 'of low specificgravitmwhich of a mold prior to the casting ofuthe product h matured in Patent N0.1,850,'743, dated March therein, showing a plate coated with abrasive or 22, 1932. Wear resistant material suspended in the mold Stair treads which are in common use are cavity. s a y P i W a t ng or wearing V .Fig. 2 is a detached fragmentary perspective face of abrasive orwear-resistant material.v A view of the plate partially coated with abrasive m n m thod ecluci es eh sta r tr ads or wear-resistant material; and, is to sprinkle the surface of the mold in which Fig. 3 is a fragmentary cross sectional view of the tread is tobe cast with comminuted resistant the finished product. a L, p a h es s a tm with a Similar numerals refer to similar parts throughsuitable binder, and then pour the' cas'ting; o tth'e drawin 7 Stair treadsproduced bythis method however, The improved product may be made by employp a W a -r is a coating w i t tn i an ordinary mold as shown in Fig. 1, having ve y h y mpre nat d i the t b dy and the cope 10 and the drag 11. The mold cavity 12 he pa c s of W ar-r t. mat a are is preferably located in thedrag as shown, and p y odged or worn Off 5 43111 has inlet and outlet gates 13 and 14 respectively, m r or ss p as m t n t e c u e d communicating with the ends of the mold cavity. does not possess the necessary frictional and The cope may be provided with a pouring sprue Wear-resistant qualitiest l5, communicating w'iththe gate 13, and with a It is therefere'desirable to p o a c sta riser 16 communicating with the gate 14. t tread Co ta commimlted wea -res a t One or more plates, which may be approxie te ia d st b te t u h a :.,h t, Such mately 28 gauge, low carbon steel, are provided a product has not, t0 0 QW 6 k ow for accomplishing segregation of the abrasive or iii-the p The difliclllty arises in 1511913111 m e wear-resistant material Within the. castv product. i su h a pr d w the o t n m t Li For convenience, one plate 17 is shownin the poured into the mold wear-resistant material drawing, I v wh h s free to move, i teth .to lei the This plate is preferably perforated as shown, ol b ca of i la y ow s fic g iw yand adapted to be anchored against displacement Accordingly, it is an Object of he li esent ni in the mold cavity during casting. Before insere v on to ea ne odflvincQr e e ti'on into the mold cavity, however, the plate 17 40 commuted abrasive or wear-'res-ista'ntrma" is thoroughly coated on all surfaces with com- 95 terial of relatively lpw'specificv-gravity ss-ubsrtanr' minuted abrasive or weareresistant material of tially segregated at a desired zone or zones inthe 10W specific gravity as indicated at 18, h as cast g a borundum, which may be applied by using a Another object i tel re id afleet neh vifie a comminuted abrasiveor wearer sistant mat r 21311321 adhesive, such as as haltum adhesive 1% of relatively low specific gravit substantially t, distributed throughout the cast ody. h i poi of th p at-e 1'1 sp e e a y These and otherobjects aie stama ty t lower than that of the metal const1tut1ng the product com rising the present invention, as b dy f th castin wh h m tal may b ast ir n,

' will be hereinafter pointed out in detail. so that during the casting operation, said plate 105 p The improved product may be made by sprinkwill become substantially entirely fused and ling abrasive or wear-resistant material v r merged with the molten metal.

the bottom surface of a mold cavity in which If desired, a fusible adhesive material, such as the product is to be cast, spraying said abrasive sodium silicate, may be used for coating the plate material with a suitable binder, suspending a l'lwi'th carborundum, so that when the casting is 1 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 mold to 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.

Preferably, the 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.

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

In making the improved product, 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 with the comminuted carborundum is againsprayed with the asphaltum binder.

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

The molten metal is then poured through the pouring sprue 15 into the mold cavity 12 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 thebottom 12' becomes gasified, some of the particles of the abrasive will be freed and begin to rise, due to their relatively low specific gravity.

As the molten metal rises to the region or zone of the adhesively 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 1s.

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 the perforations permit some of the molten metal to be forced up through the plate, with the result that any substantialwarping of the plate is obviated. It will be understood that since themetal plate 17 is relatively cold, its effect will be to chill the f 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 of abrasive material 18 is restricted, since those particles are caught in the zone of pasty metal. I

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

Likewise, a certain proportion of the particles 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 sufficiently 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 thickness 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 improved cast product produced by the herein described method is shown in cross section in Fig. 3. The segregated zone or Stratification 26 of abrasive material bodily incorporated in the mass at the outer surface of the casting corresponds in location to the bottom surface of the mold cavity, and the segregated zone or stratification 2'7 of abrasive material bodily incorporated in the mass corresponds to the relative location of the plate 17, being spaced inwardly from the outer surfaces of the casting.

The density of the zone 27 shades off or diminishes toward the upper surface of the casting as viewed in Fig. 3, and the density of the zone 26 shades off toward the zone 27, so that a substantial distribution of abrasive material is attained between the segregations or stratifications 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 offers 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. 7

When 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 oifer substantial and sat isfactory resistance to wear.

Thus a casting is produced which possesses wearing and frictional resistance substantially throughout, prolonging the life of the casting, and giving a more satisfactory performance at every stage of its life.

It is apparent that by employing a plurality of spaced plates adhesively coated with wear-resistant material of relatively low specific gravity, highly segregated wear-resistant material may be distributed substantially evenly throughout the casting to produce a cast product offering increased resistance to wear throughout the body of the casting.

Obviously, a cast product, bodily incorporating a highly segregated outer skin of wear-resistant material of substantial depth may be produced by anchoring an improved plate coated with wear-resistant material 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. e

We claim:

l. A product including a mass of'cast metal bodily incorporating spaced stratifications of comminuted wear-resistant material.

2; A product including a mass of cast metal bodily incorporating a stratification of comminuted wear-resistant material, and comminuted wear-resistant material distributed throughout the mass on each side of the stratification.

3. A product including a mass of cast metal bodily incorporating spaced st'ratifications of comminuted material of relatively low specific gravity, and comminuted material of low specific gravity distributed between the stratifications.

4. A product including a mass of cast metal embodying a stratification of comminuted wearresistant material adjacent one surface of the mass, and a second stratification of comminuted wear-resistant material bodily incorporated in the mass and spaced from the first Stratification.

Images