US1552581A - Method of and apparatus for casting - Google Patents

Description

Sept. 8, 1925.

M. C. SPENCER METHOD OF AND APPARATUS FOR CASTING Filed July 16, 1924 Fig.3.

Inventor, Millard Cole Spencer,

Patented Sept. 8, 1925,

UNHtiD sTAres arana" o aries.

MILLABD COLE SPENCER, OF EAST ORANGE, NEW JERSEY, ASSIGNOB 'IO' CROCKER- WHEELER COMPANY, OF AMPEBE, "NE-W JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF AND APPARATUS FOR CASTING.

Application filed July 16, 1924. Serial- No. 726,256.

To all whom it may concern:

Be it known that I, MILLARD COLE SPEN- can, a citizen of the United States of America, and a resident of East Orange, in the county of Essex and State of New Jersey, have invented an Improved Method of and Apparatus for Casting, of which the following is a specification.

This invention relates more particularly to the casting of the end rings for the sqirrel-cage windings of induction motors. In an induction motor there is a rotor core of laminated iron disks with a winding formed by copper bars which pass through circumferentially disposed openings in the core and project beyond the ends of the core. The projecting ends are joined to metal rings which form good electrical connection between the bars. The bars and rings constitute the squirrel-cage winding.

The object of this invention is to provide an expeditious method and suitable apparatus for the manufacture of the squirrelcages from bars of sheet metal and cast 5 rings by which an intimate union between all of the bars and the rings is assured.

In the accompanying sheet of drawings which forms a part of this description- Figure 1 is a vertical section through a flask and follow board which is used in connection with this method and apparatus.

Fig. 2 is a vertical section through the apparatus for supporting the rotor core and mold while casting.

Fig. 3 is a horizontal section through the apparatus on the line III-III.

Fig. 4 is an elevation of a portion of the apparatus for lifting the mold.

In practising this method a follow board 10 has placed thereon a suitable pattern 11 for the end-ring of the squirrel-cage, a cylindrical block 12, and a flask 18, and the flask is rammed with sand. The cylindrical block is withdrawn, leaving a clearance hole through the sand in the center of the mold, and the flask with the mold is turned over and placed on a table 14 of a casting apparatus. The follow board is lifted off and the pattern withdrawn, leaving an open mold for the end-ring.

The table is carried on a tubular column 15 which is mounted to slide on a pedestal 16. The pedestal is hollow and a bushing 17 is held therein by a set-screw 18 in a properly adjusted position. A rotor core 19, with squirrel- cage bars 20, 20 set in circumferentially disposed openings, has at its center a shouldered shaft 21. The end of this shaft is passed through the clearance hole left in the center of the mold and through a hole in the top of the table which supports the mold and into the bushing by which it is properly centered and supported at the shoulder of the shaft so that the lower ends of the squirrel-cage bars clear the top of the mold. The mold is then poured and by relative vertical movement of the sup ports for the rotor core and the mold the lower ends of the squirrel-cage bars are simultaneously plunged into the molten metal in the mold. It is not essential which of the supports is moved to effect their relative movement. As shown, the table which supports the mold is lifted. This is effected by a cam 22 on a shaft 23 with a lever 24 by which the cam is operated. The ends of the bars are held in place in the poured metal until it has had time to solidify.

I claim,

1. The process of forming a squirrelcage winding which consists in providing means for supporting squirrel-cage bars disposed substantially as elements of a vertical cylinder, and an open mold for an end ring of the squirrel-cage supported beneath the bars, pouring molten metal into the mold, plunging the lower ends of the bars into the metal by relative movement of the barsupporting means and the mold-supporting means, and holding the bars in such position until the metal has solidified.

2. The process of forming a squirrel-cage winding on the rotor core of an induction motor which consists in providing squirrelcage bars in circumferentially disposed openings in the core, supporting means for the core, and an open mold for an end-ring of the squirrel-cage supported beneath the bars, pouring molten metal into the mold, plungin circumferentially disposed openings in 10 the core, means for supporting an open mold for the end ring beneath the lower ends of the bars, and means for effecting relative movement of the core-supporting means and the inold s'upporting means by which the 15 bars are plunged into the metal.

MILLARD COLE SPENCER;

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