US995968A - Method of and means for forming molds for castings. - Google Patents

Description

A. F. HOWE. METHOD 0F AND MEANS FOR PORMING MOLDS FOB CASTI NGS.

APPLIOATION FILED AUG. 24,1910.

Patented June 20, 1911.

IWW ||||'l f1.1

IKS/m9 MM UNTTED sTATEs PATENT onnrcn ANDREW F. HOWE, OF GRANITE CITY, ILLINOIS, ASSIGNOR TO COMMONWEALTH STEEL COMPANY, F ST. LOUIS, MISSOURI, A CORPORATION OF NEW JERSEY.

METHOD OF AND MEANS FOR FORMING MOLDS FOR CASTINGS.

- Specification of Letters Patent. Patented Ju11e20, 1911.

Application led August 24, 1910. .Seria1No. 578,611.

baked in a single piece, which in being handled, baked, and re-handled, is liable to be warped or broken, so that when assembled the casting formed therein is rough and irregular; moreover, it offers resistance to the shrinkage and so causes breakage of the casting when cooling, besides obstructing the free escape of the gases from the mold, whereby blow-holes areliable to be formed in the casting. Y

My invention has for its object to insure the accurate shape of the mold, and to prevent warping and breakage of the casting from shrinkage, and waste of material.

It consists in features of novelty as heref inafter described and claimed, reference being had to the accompanying drawing forming part of this speciicatiomwhereon,

Figure 1, is a top plan view of a mold formed according to my invention, omitting the cope, and Fig. 2, a vertical cross section thereof, and through the cope, on line 2, 2,

in Fig. 1.

Like letters and numerals of reference denote like parts in all the gures.

`In carrying out 'my invention I preferably use a metallic flask awhich may beof any suitable configuration according to the nature of the desired casting,- and is in the present case rectangular, open at the top and preferably, closed at the bottom, the sldes 1 of the ask a being preferably, channel-shaped in cross section .with their ianges outward and united at the corners, and the bottom 2 similarly shapedfwith. its flanges lnward, and removably xed thereby to the sides 1 by rivets (or bolts) -3,as'shown.

From the inner face of each side 1 at suitable intervals along lthe same, project a `series of vertically downward within the aska, preferably to the top level :of similar ribsv4fwhich pro the lflask. A a from the bottom 2 and extend preferably, entirely across the flask a, either in one direction only as shown, or in both directions at right angles to and intersecting each other, or otherwise as found most desirable in practice. -On the upper edges of the bottom ribs 4 is laid a base piece (or series thereof) 5, composed of suitable baked molding material which is adapted to support a series of outer and inner sectional blocks b, b', respectively, forming corresponding parts of the mld and composed of suitable baked molding material, the blocks b, b', being arl ranged in proper order within the vflask a to form ythe complete mold, which in the present c ase is that of a rectangular I- shaped frame, the upright ribs 4 operating as gages for determining the relative positions of the blocks b, b, on their supporting base 5, that is to say, the outer blocks b, which in the aggregate form the corresponding half of the mold, are arranged longitudinally endwise against each other and later ally against the edges of the upright ribs 4, which thereby determine the alinement of the blocks b respectively, alongand at the required distance from each side 1 of the fiask a, while the inner blocks b which in c either with the outer blocks b as shown, or,

the inner blocks b as the case may be.

The spaces within the liask a unoccupied by the blocks b, b', viz: the spaces between the ribs 4, and the adjacent inner faces ofthe sides 1 and outer faces of the blocks b, the-spaces between the ribs 4 and the adjacent inner face of the bottom 2 of the flask a, and the underside ofthe base 5, and the space between the inner sides of the blocks b", are preferably filled with sand (or other suitable material) 7 which is lightly packed about the 'blocks b, b', the whole forming a complete mold which is then covered by the cope c composed of suitable baked molding material and having the ingate 8 to the mold. It is here noted that by lightly packing the sand 7 within the space between the inner blocks b', the latter are yheld suiiiclently firmly in position'to resist the pres sure of the inowing metal tothe mold, but

not sufficiently to resist the shrinking stress of .the casting 'when cooling; furthermore, owing to the rough texture of the' material composmg the blocks b, b', their abutting Ajoints are imperfectly closed, thereby affording more or less vent for the gases from the in old, and also enabling the blocks b, b", to yleldvtoward each other when subjected to' 'the shrinking stress of the casting.

The great advantage of my invention is that, by forming' each half of the mold in sections insteadof Va single piece, and adjusting the accurate alinement ofthese sections while being assembled, by predetermined fixed surfaces formed within an inclosing fiask, a perfect and uniform'mold is obtained having its parts yieldable when subjected to the shrinking stress of its contents, whereby a smooth unbroken casting produced therein 2. Ina mold for castings, the combination of a suitableflask containing a plurality of surfaces, a series of mold forming blocks arranged together in their proper order Within the flask to form the complete mold, a part of the said series beno ada ted to bear lat- "erally against the saic sur aces, and means for holding the said blocks'in place yieldably to the shrinking stress of the contents of the mold.

3. In a mold for castings, the combination l of a suitable fiask containing a plurality of surfaces, a series of mold forming blocks ar- .ranged together in their proper order within the flask to form the complete mold, a part of the said series being adapted to bear laterally-against the saidsurfaces, means for holding the said blocks in place posi-u tively against the inflowing, and yieldably to the shrinking stress of the contents of the mold.- Y

4. In a mold for castings, thevcombination of a suitable flask containing a plurality of surfaces, a series of mold forming blocks arranged together in their lproper order within the fiask to form the complete mold, a part of thesaid 'series bein adapted to bear laterally against the said surfaces, means for holding the said blocks in place positively against the inflowing and yieldable to the shrinking stress of the contents of the mold, and a cope to the mold.

5. In a mold for castings, the combination of a -suitable fiask containing a plurality of surfaces, a series of mold forming blocks ar. ranged together in their proper order withosov in the flask to form the complete mold, a

part ofthe said series being adapted to bear laterally against the said surfaces, means -for holding the said blocks in place positively against the infiowing, and yieldably to the shrinking stress of the contents of the mold, and a cope to the mold.

6. The herein described method offorming molds for castings, which consists in forming a mold cavity With sectional side Walls anda sectional bottom, maintaining the sectional side walls in proper alinement positively against outward movement, due to the infiow of moltenmetal into the Wall cavity, and yieldable to the shrinking stress of said metal, and maintaining the sectional bottom of the mold cavity positively against downward movement by reason of the inflow of molten metal into the mold cavity and yieldable to the shrinking stress of said metal.

l ANDREW Witnesses:

HAL C. BELLVILLE,

Images