US2689388A - Slip box - Google Patents

Description

H. LEARY Sept. 21, 1954 SLIP BOX 2 Sheets-$heet 1 Filed March 31, 1952 R m w W.

, HULL LEARY Hi5 HTTOQ EV SLIP BOX Filed March 31, 1952 2 Sheets-Sheet 2 INVENTOR. uu. LEARY A? 4 TTO IVEV HIS H Patented Sept. 21, 1954 UNITED STATES PATENT OFFICE t SLIP BGX Hull Leary, Philadelphia, 'Pa. Application March 31, 1952, Serial No. 279,497

1 Claim.

My invention relates to slip boxes or mold jackets used to protect and reinforce squeeze molds during the pouring of steel castings or the like.

The outside appearance of a sand mold after squeezing is quite generally that of a truncated pyramid having sides tapering inwardly at an angle of approximately four degrees. The sand mold is given the angle of taper while being pressed in a squeeze machine during which time its sides are held firm by a rigid flack whose sides are tapered at a four:degree angle.

After squeezing, the mold is opened at the parting line to remove the pattern. When reassembling the sand mold it is necessary to replace the cope on the drag so that the mold conforms in all respects to the shape it had prior to opening and the removalof the pattern.

if the reassembled sand mold does not exactly conform with the shape it had prior to being parted, the castingproduced'will be shifted and therefore unsatisfactory. The slip box which is placed over the mold after reassembly must not in any manner disturb the relationship between the cope and drag portions of the mold if a satisfactory casting is to be obtained. If the taper of the slip boxes does not exactly conform to the taper given the sand mold, the weight of a "rigid slip box will force the cope or drag to "shift so that the sides of the sand mold will conform to the taper of the slip box resultin original taper of the flask but not necessarily uniformly. Thus, it is quite possible that one or more sides may shift to an angle of, say, six degrees, while the remaining sides continue to have a taper of four degrees. It is apparent that if a heavy, rigid'slip box having uniform sides is placed on a mold whose sides vary from the true taper, the mold will be shifted or shaved to accommodate the .slip box.

The squeeze machine may .also distort the pins f the flask so that the outer perimeter of the cope does not exactly align itself with the outer perimeter of the drag. Such a condition resuitsina moldhavingacope with one side overhanging the corresponding side of the drag. When a rigid slip box is placed on such a mold the cope will be shiftedto align itself with the drag but this shift will produce a shifted, and frequently useless, casting.

In order to overcome the problem of shifting,

0 send mold with my slip box in place thereon;

in which 'I have contemplated various means have been introduced to permit the slip box to conform with the shape of the mold. These means have generally been unsatisfactory due to the fact that they required that two sides of the slip box shift together, whereas the mold, and the flask which made the mold, may not have shifted the same amount on opposite sides of the mold or .fiask. A further difiiculty has been spilling of the molten steelon the mold jacket with the consequent freezing of the adjusting means, rendering the slip-box useless. Further, manual adjustment was required.

An object of my invention is to provide a slip box having sides which may be shifted inde pendently of any of the zother sides.

.A further object =of my invention is to provide a slip box which may be racked ior canted.

A still further nbject of "my invention is to provide a slip box with protected shifting means.

A still further object of "my invention is to providea slip box whose pivotal centers will rest opposite 'the parting line of the mold.

The principles and characteristic features of my invention and the manner of making and constructing :and using my slip box will further appear in the accompanying drawings and the following description explaining the best modes using such principles.

Fig. 1 is a side elevational view of a tapered Fig. 2 is a cross-sectional,"elevational view of the mold and *slip box shown in 'Fig. 1'; Fig. 3 is a perspective view -of my slip box with the sides thereof angled at their greatest angle; Fig,

4 is an exploded view of one-side of the slip box together with theangleirons corresponding therewith; Fig. 5 is a fragmentary view of a corner of my slip'box's'howing the position of the taken along the line 8-58 ofFig. 6 'Fig. 9 is va fragmentary view of "a corner of amodified form of slip box wherein an additional pivot point is provided for a mold having a cope and drag of unequal depth; Fig. 10 is an elevational view of a mold havingone side with a different angle of taper from its opposite side; Fig. 11 is an elevational view of a mold wherein the cope has been laterally displaced with relation to the drag; and Fig. 12 is a plan view of a mold having racked sides.

The slip box comprises tapered plates I, joined by angle irons 2 having openings 3 and 4 inter-. mediate the ends thereof. Spaced openings 5 of the same diameter as the holes 3 are provided in the plates I opposite the openings 3 and 4 through which bolts 6 are passed and secured by nuts I. The-pivot or parting line openings 3 and the openings 5 are of approximately the same diameter as the bolts 6 but the openings 4 are preferably about twice the diameter of the bolts 6. Thus, each side plate I is able to turn or pivot an amount equal to the difierence between the diameter of the holes 3 and 4.

The perfect mold has sides58 and 9 (Fig. 1) which taper inwardly at the same angle, 4 degrees, and has a cope which registers exactly on the drag. Where, however, a mold is formed in a flask having sides of differin angles of taper a mold is produced which may be similar to that shown in Fig. 10 wherein the side I0 tapers inwardly ata substantially greater angle than the opposite side II. If a slip box having rigid sides is placed on such a mold, it will force the mold to assume the shape of the slip box either by shaving off the distorted side or by compressing the mold.

A distorted flask or flask pin may form a mold in which the cope I2 is offset on the drag I 3 as illustrated in Fig. 11. If a slip box having rigid sides is placed on such a mold, it will shift the cope or drag until the sides of the cope register with the sides of the drag.

In either of the above instances the pattern formed by the core (not shown) will'be shifted and the casting poured from such a mold will be imperfect.

In my slip box the side plate I may be angled about the pivot bolts 6 to accommodate any reasonable distortion in the mold. In order to pivot, the side plate I turns about the two pivot bolts 6 contained in the face of the angle irons which are at'right angles to the plane of the side plate to be moved. The amount ofturning is limited by the size of the openings =4 oreby the distance between the rear-face I8 of the angle irons in the plane of the plate being pivoted and the end of the Side plates perpendicular ,to the side plate being pivoted, as shown in Figs. 5 and 6. The nuts I are secured to the bolts 6 in such manner that the platesI are able to'move along the face of the angle irons 2 without undue friction.

Each of the plates I and angle irons 2 are completely interchangeable and readily replaceable andcan be assembledor disassembled and stored in a minimum amount of time and space. Should one of the plates bedistorted accidentally it can be readily removed and replaced by another thus resulting in slip boxes which give a maximum amount of use and a minimum amount of discards,

I protect the angle irons and bolts from being frozen by molten metal by providing a splash plate I4 along the top of each angle iron. When, as sometimes happens, molten metal is spilled the splash plate Ill shields th bolts 6 and nuts I from molten metal and eliminates the possibility of immobilization of, the slip box.

I provide for the openings 3 to be at the parting line H of the mold as this provides a point about which maximum effect is derived from the pivoting. Because of the shape of the article to be cast, it is not always possible to use a mold having the same depth of cope as of drag. I have provided for this contingency by having additional pivot point openings I5 in the side plates and angle irons Fig. 9. By shifting the pivot bolt from opening 3 to opening IE, or the reverse thereof, I provide more cover protection to the cope or to the drag as may be desirable, thus reducing the number and variety of slip boxes which must be kept in inventory. R

It sometimes happens that a mold is formed which is out of square. My box can rack sufficiently to accommodate out of square boxes or to accommodate buckling due to heat. This is possible because of the substantially friction free relationship between the'angle irons and the sides. A mold such as described is illustrated in Fig. 12.

Rigid slip boxes are frequently burned and buckled when hot gases attempt to escape from the mold during the pouring operation. My slip boxes allow these hot gases to escape harmlessly at each corner inasmuch as a venting space I6 is provided at each corner of the box. As the hot gasses can escape easily and quickly up these vents the danger of overheating the slip boxes and consequent buckling is substantially eliminated.

It is to be understood that I have merely illustrated the preferred embodiment of my invention and the provision of additional pivot openings or variations in the placement of the safety openings 4 are not outside the scope of this invention.

Having described my invention I claim:

An automatically adjustable slip box for a tapered mold comprising a plurality of rectangular plates having a plurality, of identically sized apertures adjacent the longitudinal extremities, one of said apertures at each of said extremities being located on approximatel the longitudinal axis of saidplates, a plurality of angle irons connecting said plates and having apertures in juxtaposition to the apertures in said plates, the apertures in said angle irons opposite the apertures on the longitudinal axis of said plates being of substantially the same size as the apertures in said plates and the-remaining angle iron apertures being substantially larger than said plate apertures, screw bolts projecting through said apertures and nuts loosely applied to said'screw bolts permitting the said plates to freely and independently pivot about said bolts in the apertur-es along said longitudinal axis for automatic adjustment to the taper of said molds.

References Cited in the file of this patent UNITED STATES PATENTS

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