US1534655A - nichols - Google Patents

Description

April 21, 1925. P 1,534,655

w. H. NICHOLS MOLD Original FiI d Jan. 10, 1921 2 Sheets-Sheet l April 21, 1925.

' W. H. NICHOLS MOLD Original Filed Jan. 1Q, 1921 2 Sheets-Sheet 2 INVENTOB Patented Apr. 21, 1925.

UNITED STATES PATENT OFFICE.

MOLD.

Continuation of application Serial No.

To all, whom it may concern:

Be it known that I, WILLIAM H. Nrorrons, a citizen of the United States, and resident of Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Molds;

and I do hereby declare the following'to be a full clear, and exact description thereof. -My invention" relates to molds for formmg the necks of rolls cast in groups or clusters, 'nd for similar purposes, and it relates particularly to drag molds for use in casting clusters of rolling mill rolls.

The'object of my invention is to provide an improved sand mold for simultaneously casting-two aiticles having horizontal runners in line with, each other and embedded in the sand. In preparing such a mold it is a diificult matter to remove the patterns which form the runners. An important feature of my invention is the provision of a method of removing patterns from a mold of the kind described, this method consist-' ing, in general, in providing an additional pattern which is removed after the mold is tamped and which gives access to the runner patterns. The opening or openings left by the additional pattern are then closed by means oficores previously formed from molding sand or the like. This method of molding is set forth and claimed in my application for Letters Patent filed Nov. 1, 1922, Serial No. 598,360, of which the present application is a division.

In my Patent 1,455,091, issued May 15, 1923, I have described and claimed a novel method of casting chill rolls consisting in arranging a plurality of molds around a common upright pouring gate and pouring molten metal simultaneousl upright gate into all of t e molds. As shown in said patent, the chills and the upright gate-box are all mounted upon a common drag flask in which the neck cavities, horizontal sprue-runners and the lower end of the upright pouring gate are molded in sand.

My prior application, No. 598,360, and also the present application, are continuations of the Patent 1,455,091 mentioned 435,815, filed January 10, 1921. 1924. Serial No. 699,044.

through the This application filed March 13,

above. The present application is specificall 5 concerned with the mold structure descri ed herein.

It will be understood that the principles of my present invention may be employed in making molds for other articles than rolling-mill rolls and particularly in making molds wherein two or more molding cavities are connected by means of runners witha common pouring gate.

In the accompanying drawing, Fig. 1 is a verticalsectional view through a group of chill molds arranged for casting rolls according to my above-mentioned patent, and provided with a drag mold constructed according to my present invention; Fig. 2 is a plan view of the drag flask and patterns; Fig. 3 is a vertical sectional view of the drag flask and patterns slfown in Fig. 2; Fig. 4 is a vertical sectional view similar to Fig. 3, showing the flask filled with sand and inverted preparatory to removing the patterns; Fig. 5 is another vertical sectional view similar to Figs. 3 and 4:, showing the manner in which the sprue patterns are removed; Fig. 6 is another vertical sectional view similar to Figs. 3 to 5, showing the final appearance of the mold after the patterns have been removed and the core blocks placed over the sprue runners; Fig. 7 is a plan view ofthe shown in section on Fig. 6; i g. 8 is a detail plan view showing the construction of the patterns used in molding the sprue runners; Fig. 9 is a detail plan view showing the core blocks which are placed over the inner portions of the sprue runners after the patterns have been removed; and Fig. 10 is a detail showing in vertical section the relation between the core blocks and the sprue runners.

In the drawing the numeral 2 indicates a metal drag flask designed for casting four chill rolls. In order to receive the neck molds for the four rolls, the flask 2 is pro vided withrfour recesses 3 of generally circular form which communicate with a common central space through straight channels 5. I Fig. 8 shows a wooden pattern consisting complete drag mold 4 In assembling the mold patterns, the flask 2 is placed in proper position on the follower plate 7, the cross 10 is set in the center of the flask, the sprue patterns 6 and 12 are then laid upon the arms of the pattern member 10, as shown in Figs. 3 and 8, and

the neck patterns are placed in position at the ends of the sprue runners, with their pins 14 inserted in the openings 9. A little sand should be placed under the projecting sprue patterns 12, as shown at 15, Fig. 3, in order to prevent these patterns from tipping over. Molding sand is then tamped into the flask in the usual manner, care being taken that the sand shall be forced beneath the sprue patterns 12.

After the sand is tamped in the flask, the flask is inverted upon a suitable bottom plate 16, as shown in Fig. 4. The neck patterns 13 are then lifted out, and the four.

armed pattern member -10 is also lifted from the sand. This leaves the sprue patterns still embedded for a portion of their length within the sand. In order to remove these sprue patterns the inner pattern sections 6 are lifted, as shown in Fig. 5, leaving room for the outer sections 12 to be pulled length wise into the open space left by the fourarmed pattern 10. The sections 12 are pulled horizontally one by one in the manner stated, and are lifted sidewise and vertically from the mold.

The spaces originally occupied by the four arms of the pattern member 10 are then filled with core blocks 17 previously molded from molding sand and o proper size to fit in these openin s, and covering the sprue runners 18, as s own in Figs. 6, 7 and 10. The neck cavities 13 are then finished and coated in the usual manner, and the drag is ready for use as shown in Fig. 2. When the drag is assembled with the chills and upright ate box, substantially all of the upper surace of the sand is covered by these parts which prevent the sand from bein forced up above the sprue runners during t e pouring operation. The arms of the cross pattern 10 have their sides tapered slightly, as shown in Figs. 3, 4: and 10, in order that this pattern may be readily lifted from the sand, and the sides of the core blocks 17 are similarly tapered.

Fig. 1 shows the complete assembly of the group of chill molds, including the drag mold described above, chills 20, upper boxes 21, sink heads 22, and an upright gate box 23 to the upper end of which is secured a funnel 24. The vertical opening 25 in the upright gate box is in line with the central opening 26 in the upper surface of the drag mold, and the sprue runners 18, molded in the manner described above, communicate radially with this central opening 26 and enter the neck cavities 13 tangentially in order to produce the proper swirling movement of the metal.

In the operation of the mold shown in Fig. 1 to form a group of rolls, the molten metal is brought to the mold in a ladle and is poured into the funnel 24, whence it passes down through the horizontal sprue runners 18 into the lower portions of the molds. Some of the molten metal remains in the central cavity 26 and serves as a cushion to prevent the descending metal from splashing.

It will be observed that the sides of the sprue runners 18 converge before entering the neck cavities of the molds. This givesv a nozzle effect, causing the molten metal to be injected into the molds more forcibly than would be the case if the sprue runners were of uniform cross section throughout their length.

After the rolls are cast the chills and the upper boxes are removed and the cast rolls are lifted from the drag. Since there is nothing at this time above the sprue runners 18 except molding sand, the metal which has solidified in the horizontal runners is easily lifted from the drag, sometimes carrying with it the molding sand, and at other times breaking through the molding sand.

I claim as my invention:

1. A mold comprising a plurality of cavities molded in sand, a common pouring gate, and runners connecting said pouring gate with said cavities, the ends of said runners adjacent to said cavities being wholly embedded in the sand of said mold, and the remaining portions of said runners having their tops closed by means of blocks formed. separately from said mold.

2. A drag mold for casting the necks of a group of rolls, comprising a plurality of neck cavities molded in sand, a central ate opening, and sprue runners 'exten ing radially from said central gate opening to said neck cavities and opening tangentially into said neck cavities, the outer ends of said sprue runners being wholly embedded in the sand of said mold and the inner ends group of rolls, comprising a plurality of neck cavities molded in sand, a central gate opening, and sprue runners extending radially from said central gate opening to said neck cavities and openmg tangentially into said neck cavities, the outer ends of said sprue runners being wholly embedded in the sand of said mold and the inner ends of said runners, adjacent to said pouring gate, being tapered and having their tops closed by means of blocks formed separately from 10 said'mold. I i

In testimony whereof I, the sald WILLIAM H. N IoHoLs, have hereunto set my hand.

WILLIAM H. NICHOLS.

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