US2775803A - Chill plates - Google Patents

Description

out

Jan. 1, 1957 FiledMay 18, 1955 V. E. ZANG ET Al..

CHILL PLATES 2 Sheets-Sheet l INVENTOR. vlctor E. Z us By Emmett: E. ompson ATTORNEY Jan. 1, 1957 v. E. ZANG ETAl.

CHILL PLATES 2 Sheets-Sheet 2 Filed May 18, 1955 INVENTOR. Victor E. Zamg y Emmett E.Thompson M wm ATTORNEY United States Patent CHILL PLATES Victor E. Zang and Emmett E. Thompson, Toledo, Ohio Application May 18, 1955, Serial No. 509,150 8 Claims. (Cl. 22160) This invention relates to chill plates, and, more particularly, to the provision of magnetic means in a pattern for holding chill plates during the forming of a mold or core.

Chill plates are frequently required in molds and cores used for producing castings. Where the section of a casting varies appreciably, it has been found that defects are frequently encountered in the thicker sections if, for example, a green sand mold is produced and molten metal poured therein to produce the casting. Such defects are attributable to a slower cooling of the thicker sections which results in a pool of molten metal on the interior of the thicker portions after the remainder of the casting has solidified. As the casting cools further, shrinkage occurs, leaving a void or defect in the interior where a portion of the molten pool had been. Itv is known that suitably sized pieces of metal, called chill plates, can be incorporated in a sand mold or a core ad-j jacent the thick sections of the mold cavity to prevent such defects by increasing the solidification rate.

Various techniques have heretofore been suggested for holding chill plates in proper position on a pattern during the formation of a mold or core. 'For example, chill plates have been incorporated in a flask, as an integral part thereof. chill plates. have also been used, either alone, or in combination with recesses in the flask or pattern, to"

hold chill plates.

While the use of a chill plate which is an integral part of a flask is satisfactory metallurgically, this requires the fabrication of a special flask for each part that is to be cast. The positioning of chill plates in a mold by means of pins which pass through either the pattern or the flask is a tedious, time consuming procedure. Chill plates held by pins are likely to tear loose during molding necessitating repairs, and the pins must be removed, either during cleaning or before casting. So far as is known, no fully satisfactory way has heretofore been available for holding chill plates in position while a green sand or other mold or core was formed therearound.

The instant invention is based upon the discovery that magnets suitably positioned in a pattern can be used to hold chill plates in position during the production of a green sand mold, a baked sand mold or core, or a shell or other mold or core.

It is, therefore, an object of the invention to provide an improved means for holding chill plates in position during the formation of a mold or core around a pattern.

It is another object of the invention to provide a pattern having, embedded therein, a suitably positioned magnet for holding a chill plate during the formation of a mold or core therewith.

Other objects and advantages will be apparent from the description which follows, reference being had to the accompanying drawings, in which- Fig. 1 is a view in perspective, with parts broken away, of a molding box with green sand packed therein Numerous pin devices to holdaround a pattern to which chill plates are adhered by magnets embedded therein;

Fig. 2 is a view in elevation of a magnet and an adjusting means associated therewith;

Fig. 3 is a view in perspective of a chill plate;

Fig. 4 is a view in vertical section along the line 4-4 of Fig. 1 showing the particular assembly of magnet, pattern and-chill plate of Fig. 1;

Fig. 5 is a view in vertical section showing a portion of a completed mold with the chill plate of Fig. 4 embedded in a cope and in assembled position relative to a cooperating drag;

Fig. 6 is a view in vertical section similar to Fig. 4, but showing a magnet holding a chill plate in a generally vertical position relative to a pattern;

Fig. 7 is a view in vertical section along the line 7 7 of Fig. 6; and

Fig. 8 is a vertical sectional view similar to Fig. 5

showing a cope carrying a chill plate in a vertical position in assembled relationship with a cooperating drag. Referring now in more detail to the drawings, and especially to Figs. 1-4, a molding box indicated generally by the numeral 11 has, appropriately positioned therein and affixed thereto, a pattern 12. The particular pattern 12 shown has a plurality of bosses 13 on which are positioned chill plates 14. Green sand 15 has been packed in the box 11 around the pattern 12.

As will be apparent from Fig. 4, a magnet 16 is suitably positioned in each of the bosses 13, as by a retainer 17.threaded into the pattern. The magnets 16 can be of any suitable type, but are preferably made of bar stock, for example of the type commercially available under the trade designation Alnico. In the specific embodiment of the invention shown, the magnets 16 can be raised or lowered from the position shown by suitable adjustment of the retainer 17. Raising the magnets brings :on the chill plates must be sufficiently great to prevent displacement of the latter by the sand 16 as it is packed around the pattern, for example in a conventional squeeze jolt molding machine. This force, however, must not be so great that the chill plates are removed from the cope or drag in drawing the pattern from the mold. It has been found that the magnets 16 can easily be positioned by suitable adjustment of the retainers 17 so that the chill plates 14 are adequately locked in position to withstand the impact of sand during mold formation, but readily separate from the pattern when the latter is moved in the direction of the arrow in Fig. 4 in drawing the pattern from the mold.

A portion of the cope produced in the mold box 11 against the pattern 12 is shown in Fig. 5 in assembled relationship with-a drag 18 to define a mold cavity 19.

It will be observed that the mating line between the chill plates 14 and the pattern 12, as shown in Figs. 1 and 4, is approximately horizontal. It has also been found that a chill plate 14, for example, can be temporarily attached, as described, to a round, or angular or inclined surface, or to a vertical surface of a pattern 20 as shown in Figs. 6 and 7 by a magnet 16, which can be for example positioned by a retainer 17 threaded into the pattern 20. The chill plate 14 is clamped against the pattern 20 so that, when green sand is packed therearound to produce a cope 21, slippage of the chill plate is prevented. The pattern 20 is moved in the direction of the arrow in Fig. 6 to separate it from the mold. Where required, a surface of a magnet can also be ground to receive a non-planar chill plate.

The cope 23. is shown in Fig. 8 mated with a drag 22 to form a mold cavity 23.

Magnets can be embedded in a pattern made of metal, Wood, or other suitable material to support chill plates according to the invention. Thetechnique of a' chill plate-supporting magnet embedded in' a pattern is ap-' plicable to green sand molding as shown in Figs. 1-8, and is also equally operable in the productionofbaked sand molds and cores, shell molds and cores, andeven of investment molds and cores, when chill plates are' required. The technique involved in using magnets to support chill plates in baked sand coresand. molds, shell molds and cores, and the like, is identical with that for greensand molding.

It'will'be apparent that various changes and modifications can be made from the specific details discussed'and shown in the attached drawings without departing from the spirit of the invention. In its essential details, the invention provides a mold assembly comprising, in combination, a pattern, a mold-formingmaterial surrounding at least one surface of the pattern, a magnetembed'ded in the pattern, and a chill plate held against'aportion' of the pattern by the magnet, and surrounded by' the mold-forming material, and'the recited patternmagnet assembly.

What we claim is:

1. A mold assembly comprising, in combination, a pattern, a green sand mold forming'material surroundingat least one surface of said pattern, a generally rod shaped magnet slidable in a recess in said pattermm'eans threaded into said pattern, and engaging said magnet, for supporting said magnet in any of a plurality of positions relative'to said pattern, and a chill plate held against a portion of said pattern by said magnet, and embedded in said green sand.

2. A mold assembly comprising, in combination, a pattern, a mold-forming material surrounding at least one surface of said pattern, a generally rod-shaped magnet embedded in'said pattern, means for adjusting the position of said magnet axially relative to said pattern surface, and a chill plate held against a portion of said pattern by said magnet, and surrounded by said mold-forming material.

3. A mold assembly comprising, in combination, a'

pattern, a mold-forming material surrounding at least one=surface-of said pattern, a magnet embedded in said pattern, said magnet having a surface which is approximately aligned with said pattern surface, means for changing the position of said magnet, whereby said magnet surface is moved at an angle relative to said pattern surface, and a chill plate held against a portion of said pattern by said magnet, and surrounded by said moldforming material. 10 4. A mold assembly comprising, in combination, a

pattern, a mold-forming material surrounding at least.

one surface of said pattern, a magnet embedded in said pattern, and a chill plate held against a portion of said pattern by said magnet, and surrounded by said moldforming material.

5. A pattern having at least one contoured surface for forming a mold part, a generally rod-shaped magnet slidable in a recess in said pattern, and means threaded into said pattern, and engaging said magnet, for supporting said magnet in any of a plurality of positions relative to said pattern.

6. A pattern havingat least one contoured surface for forming a mold part, and a magnet embedded in said pattern.

7. A pattern having at least one contoured surface for forming a moldpart, a generally rod-shaped magnet embedded in said pattern, and. means for adjusting the position of said magnet axially relative to said pattern surface.

00 8. A pattern having at least one contoured surface for forming a mold part, a magnet embedded in said pattern, said magnet having a surface which is approximately aligned with said pattern surface, and means for changing the position of said magnet, whereby said magnet surface is moved at an angle relative to said pattern surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,127,095 Sands Feb. 2, 1915 1,130,066 Carter Mar. 2, 1915 1,833,128 Robe Nov. 24, 1931. 2,052,921 Dockray et a1. Sept. 1, 1936 4 2,672,664 Sudziarski Mar. 23, 1954

Images