US2458410A - Process of casting - Google Patents

Description

Jan. 4, 1949. H I '4 o. F. PARSONS PROCESS OF, CASTING 3 Sheets-Sheet 1,

Filed April 16, 1945 INVE N TOR Jan. 4, 1949. o PARSONS 2,458,410

PROCESS OF CASTING Filed April 16, 1945 3 Sheets-Sheet 2 INVE/V TOR 04m Wm 0. F. PARSONS PROCESS OF CASTING Jan. 4, 1949.

v s Sheets-Sheet :5

Filed A ril 16, 1945 R.. m w

Patented Jan. 4, 1949 raooass or cas'rma outer 1?. Parsons, Phoenix, Aria, asslgnor to a. A.

Spring, Phoenix, Aria, and

Denver, Colo.

T. E. Norman,

Application April is, 1945. Serial No. 588,601

2 Claims. (01. 22-209) This invention pertains to a method of casting metal balls, or the like.

Heretofore, means have been devised and proposed for rapid multiple casting wherein a series of fixed moulds were poured successively and opened automatically after the casting metal chilled. However, none of these means has been made fully automatic, since sprue and riser neck moulds had to be prepared and set in place above the moulds by hand before pouring. Neither did these means eliminate the formation of sprue or riser necks. It has heretofore been necessary to not only remove the sand mould material from the casting, but to remove sprueneckstherefrom as well.

In view of the foregoing, one of the objects of my invention is to provide a method wherein balls, or other similar objects, may be cast from molten metal in fixed or permanent moulds, without the formation of a sprue neck'or riser.

A second object isto provide a method for multiple metal casting wherein pressure necessary to fill out a mould is imparted to metal entering the mould by a pool of molten metal and applied in a manner so that no sprue neck or riser is attached to the casting.

A third object is to provide a method of casting objects of metal in a multiple permanent mould in a manner so that the mould is filled from a pool of metal and moves from under the pool after partially chilling but while the upper portions of the casting are in a sufficiently fluidstate to reject the metal of the sprue necks ,by pouring when tilted to a desired'angle.

A fourth object is to provide a method wherein a series of sectional two-part moulds arranged so that the parts composing the several moulds can be brought together successively to form completed moulds poured from a superposed pool of melted metal, moved from beneath this metaL.

before the sprue neck 'hardens and then opened to reject the casting after it has chilled and hardened: and

A fifth object is to provide a method for easting metal grinding balls without sprue necks or other protrusions and so that they may be used immediately after casting without trimming.-

Other obiects will appear hereinafter.

I attain the foregoing method by means of the machine, mechanism and devices shown in the accompanying drawings, in which Figure 1 is a. front elevation of the machine; Fig. 21s a side elevational view of the same. Fig. 3 is a transverse section taken of Figure 4.

on line l-4 on Shaft I, which is journaled in bearings 4 and 5. extending from base 6. This wheel carries a mould ring I.

A chain l running over double sprocket wheels H and I 2 carries mould blocks l8, and engages a portion of the periphery of the mould ring. The sprocket wheels are supported on shafts H and II respectively. Shaft i5 extends to the back of the frame and carries a gear It by means of which this shaft may be driven at a predetermined desired speed.

The mould ring 1 is preferably cast of copper. Moulds are formed between portions of this mould ring and each of the several mould blocks 83. Cavities i8, forming approximately half of the mould area, are formed at equally-spaced intervals around the periphery of the mould ring.

A sprue hole I 9 leads radially inward from the innermost depth each of these mould ring cavities.

The inner face of the ring is provided with an annular channel IT, with its bottom generally following the contour of the mould cavities. Ex- .ntension flanges are attached to the inner rims ii on each side of this channel and have a 2 section. The annular space between these extensions is filled with fire-resistant refractory cement 29, as shown in Fig. 3 to form a V-shaped annularpouring trough 23.

The chain 00 is composed of pairs of inner links 24 and outer links 25, Joined by cross-pins 28. Mould blocks ii are held between each pair of links on 'pins 21 extending into each-side of each mould block near its forward upper portion. The link pins 26 extend beyond the outer links sufllclently to form sprocket-engaging bosses 28 which fit into notches 30 on the rims of the two plates 3i and 32 of sprocket wheel l2. They ride on the rims of the plates of sprocket wheel ii.

' Fig. 4 is an enlarged fragmentary front view partly broken away. Similar numerals refer to similar parts in the several views.

Mould wheel 2. formed as a disk, is mounted Since this wheel merely idles no notches are necessary.

The mould blocks are preferably made of copper. Each block has an upper face 35 conformable to the periphery of the mould ring. A cavity 36 is formed in this face as a mating complementary part of a mould cavity in the ring. Lugs 31 depend from the lower part of the block and form bearing supports for a roller 88. At each end of each block, just below the face, there are transverse grooves 39 sized to clear link pins 26, and to provide a stop for the rear end of the mould by engagement of the pin on the .lip 40 formed along the upper edge of the rear groove.

The chain. carrying these moulds, is arranged on its sprockets so that it travels from left to right along its upper course. Sprocket i2 does the driving. Both sprockets are composed of two plates, as above explained, so that the mould blocks can ride between them. The upper course or the chain is tangent to or in contact with the periphery of an arcuate portion of the mould ring. A number of mould blocks are, therefore,

always in contact with the ring. These blocks are spaced on the chain so that they register with the positions of mould cavities on the ring. To drive wheel 2, and coordinate the movement of the chain and wheel, I provide bosses 43 on the outer face of the mould ring positioned and arranged to be engaged by notches 44, formed in extensions 45 of outer links 25. An arcuate track 45 is positioned below the upper course of chain II) to support rollers 38 on each mould block as it passes through the contacting arc with the ring. Springs 41 form a resilient support for the track.

- At the right end, this track is provided with an angular break-off or drop lip 48, positioned so that, as each mould block leaves or breaks away from the mould ring, the rear edge of the block is dropped sharply away from the ring by roller 38 moving over the hump 50 of the track and dropping rapidly to the right on the angularly downward portion of the lip 48. This prevents binding of castings in the mould parts at the moment of separation or breakaway" of the mould parts.

In use, melted metal is poured into annular trough 23 from pouring chute 55. The wheel 2 and mould ring are rotated in a counter-clockwise direction by chain l0, driven by sprocket it. A pool of melted metal 56 forms and remains in the bottom of the trough 23 as the ring rotates. Moulds are closed throughoutthe pouring area or are from 58 to 5B. As unfilled moulds enter the pouring area they are filled from pool 56. The chute 55 introduces the hotter metal at the right or departing side of the pool. As the filled moulds leave the metal pool their sprue holes are brought into contact with the hot fresh melted metal. The moulds are first filled as they enter the area under the molten metal pool. This fill solidifies and shrinks, progressively from the bottom of the mould toward the top where the spue neck is located. As the mould travels under the pool its upper part is brought in contact with increasingly hotter melted metal which fills voids caused by shrinkage and maintains the upper part of the casting in a fluid state, so that, as the casting emerges from the pool, the small column of metal remaining in the sprue neck is drained back into the pool, assisted by contact with hot metal flowing from chute 55, which adds sumcient heat to keep this sprue metal in a fluid state. Thus, it will be seen, the moulds move into a filling and pouring area, being supplied progressively with hotter metal as they continue to move and so that the upper part of the casting is maintained in a fluid state until it is carried up the departing side of the pouring arc.

The moulds, being made of a highly heat-conductive metal, chill the casting rapidly, and by the time the mould reaches the breakaway point 50, the castings are sufilciently solid to be removed from.the mould. After the mould parts separate at the breakaway the casting 62 is carried on its mould block over the bend in the chain l as it follows around sprocket wheel l and are there dropped out, as the wheel continues to turn, and deposited in trough 63.

Obviously, the mould ring and blocks may be cooled by various means where the nature of the work requires rapid operation. Thus, the upper part of the ring may pass through a chilling hood, and the mould blocks on the bottom course of the chain may pass through water. Or, all may be jacketed and cooled by fluid or chilled air.

Whereas, I have illustrated the machine as applied to casting grinding balls or the like, it

will be apparent to those familiar with the art that the mould ring and mould blocks may be changed to produce castings of many varied shapes.

Many changes and modifications of the illustrated construction may also suggest to those familiar with the art, all of which, however, may well remain within the spirit of the invention. Therefore, I wish to be limited only by the following claims:

I claim:

1. The method of casting metal which comprises moving a series of mold sections in a circular path about a horizontal axis, moving a second series of mold sections in a path so that the sections of the first and second series are brought into assembled molding relation throughout an arcuate portion of their travel, supplying molten metal to form a pool directly upon theassembled sections so as to successively fill said molds through openings in the top thereof and in direct communication with the pool and wherein the temperature of the molten metal of the pool increases as the assembled'sections move through their filling travel.

2. The method of casting metal which comprises moving a series of upper mold sections in a circular path about a horizontal axis on a support providing an annular trough therein, moving a series of complementary bottom mold sections in an endless path so that the upper and lower section are brought into assembled molding relation throughout an arcuate portion of their 'travel. continuously pouring molten metal into the trough to form a pool in the bottom part thereof and upon the assembled mold sections so as to successively fill the molds through openings in the top thereof, the molten metal being fed into the trough in such manner as to cause the metal entering the molds to increase in temperature as the assembled molds move through their filling travel.

OLIVER F. PARSONS.

REFERENCES CITED The following references are'of record in the file of this patent: v

UNITED STATES PATENTS

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