US2621381A - Pattern for horizontal casting systems - Google Patents

Description

De'c; 16 1952 s a G N 0 HM d R 8 mid/AZ A Patented Dec. 16, 1952 PATTERN FOR HORIZONTAL CASTING SYSTEMS William H. ohnson, Washington, D. 0. Application May 4, 1950, Serial No. 159,912 4Claims. (01. 22-157) (Granted under the act of March 3, 1883, as

This invention relates to the improvements in the casting of metals more particularly to new systems for the pouring of, metals in horizontal casting and to pattern plates for the molding of foundry cores which embody the new pouring systems'of the invention.

Horizontal casting of metal as commonly carried out in the foundry involves a system including a straight runner to which is connecteda series of horizontally arranged'conduits, called finger gates, which lead' into the casting mold or cavity. Thesprue may feed to the end or center of the runner which is of the conventionally larger size and equal in cross-section to the sprue. The larger size runner providesadequate volume in the runner for flow of the metal equally to all of the finger gates. The art has worked to attain smooth, quiet, uniform flow through all the-finger gates but experience has shown this desirable result to be seldom obtained. With the use of a runner and finger gates of the conventional larger size, the metal generally tends to flow more copiously through some of the finger gates than others with resulting uneven flow of the metal into the mold. This uneven flow of the metal develops local areas of turbulence in the casting mold with the result that dressing occurs in the case of non-ferrous metals. If on the other hand, the finger gates are made small enough in cross-section to obtain uniform flow therethrough, the metal is propelled into the casting mold under a terrific jet action which develops'a large degree of turbulence in'the mold giving rise to sand erosion and possible poor surface appearance'of the casting, and in'the case of non-ferrous metals, dressing as well.

It is an object of the present invention to provide an improved system for the pouring of metal in horizontal casting.

It is a further object of the invention to pro' vide an improved system or method for the pouring of metal in horizontal casting in which smooth, quiet uniform flow of the metal through all of the finger gates can be obtained without the necessity of resorting to finger gates of small area or cross-section.

' It is another object of the invention to provide pattern plates from which can be molded foundry forms embodying the new pouring systems of the invention.

Other objects of the invention will become ap parent from the description thereof which follows:

Briefly stated, I have found that metals can be induced to flow through all the finger gates in a amended April 30, 1928; 370 O. G. 757) 2 smooth, quiet uniform manner to the casting mold of a horizontal casting system, with the advantages of materially reducing turbulence in the mold and the resulting undesirable results,

by providing in combination a split-pool runner to which is connected an even multiple of equi spaced finger gates, at least four, which lead to the casting mold or cavity.

In another aspect of my invention, I have pro-- vided pattern plates for the new pouring systems from which, in the usual way, can be molded foundry cores which embodythe new pouring systems. These pattern plates carry on a broad face thereof a raised design of the new pouring systems, the raised design taking the form of a series of interconnected bosses corresponding to the several elements of the pouring system.

The split-pool runner is formed of spaced en larged sections or pools of equal size which are interconnected by means of a neck portion or passagewayof reduced cross-section. In opera-i tive position, the runner is placed with the neck portion at the top, with the pools extending downwardly'therebelow. The finger gates are connected at the upper part of the. runner, lying flush withthe top edge thereof, and are equally spaced along the length of the runner. The spacing ofthe finger gates is also such that the pools terminate within th space defined by the two centralifinger gates and at about equal distances therefrom.

While there is shown herein by way of 111115: tration a split-pool runner having but two pools, obviously, the principle underlying the construc-- tion of the runners of my invention may be embodied in like runners having three, four or five or more'p'ools interconnected by means of an appropriate number of neck portions. I Suitably, the' split-pool runner of my invention is constructed in such proportions that the pools or enlarged sections have a length equal to about five and one-half times the length of the neck portion and a depth equal to about twice that of the neck portion; The neck portion of the runner is equal in cross-section to that of the sprue for feedin the runner which is done at the center thereof. As previously mentioned, the finger gates may be provided in equal mul-' tiples along the length of the runner, with a minimum of four. The finger gates are of smaller cross-section than either the sprue or thene'ck portion and the sum of their cross-sectional areas is at least twice the cross-sectional area of either the sprue or the neck portion of the runner.

The split-pool runner of my invention functions to direct the flow of metal to the outer finger gate so as to promote even flow into the casting mold through all of the finger gates. It has the further advantage of saving metal as against the single chamber, conventional runner of constant cross-section in that large quantities of metal are not sent through an area of the runner where it is of least use, i. e. the central portion thereof.

The invention will be more fully understood by reference to the following description taken in conjunction with the accompanying drawing in which like parts carry like numerals and in which:

Figure l is a perspective view of a pattern plate carrying a raised design of an improved pouring system of the invention, and

Figure 1A is a schematic showing, in operative set up with a casting mold or cavity, of the improved pouring system forming the subject matter for the pattern plate of Figure 1. v Referringto Figure 1A, the usual sprue (not shown) leads to the center of a split-pool runner I having enlarged sections 2 and 3 interconnected by means of a neck portion 1. A series of four flat-bottomed finger gates 5, E5, 7 and 8 of equal cross-sectional area and of a depth less than that of the neck portion 4 are connected to the upper portion of the runner i and lie flush with the top thereof. The inner ends of the pool sections 2 and 3 are shown as terminating within the space defined by the central finger gates 6 and l and spaced an equal distance from each. The finger gates extend from the runner in a plane trans verse to the vertical axis of the runner and lead into the casting mold or cavity 9 shown in conventionalized form. In the construction of the pouring system shown in Figure 1A, the sprue and the neck portion 4 of the runner are of equal cross-sectional area. The pools 2 and 3 are equal in width to the neck portion 4 and are of length five and one-half times that of the neck portion. The sum of the cross-sectional areas of the finger gates is twice the cross-sectional area of the neck portion 4 or of the sprue.

In operation of the pouring system of Figure 1A, a metal, for example, steel or brass, is poured into the sprue and enters the runner I at the center thereof filling up the pools 2 and 3.

The pools serve to reduce the momentum of the metal feed and direct the flow of the metal to the other finger gates and 8 so as to bring about an even flow of the metal through all the finger gates into the'cavity mold 9. The flow of the metal in the system is quiet, smooth and uniform.

In Figure 1, pattern plate 0 is shown provided'with a raised design in full cross-section of the pouring system of Figure 1A. The raised design is constituted by a series of connected bosses which correspond to the elements of the pouring system and are identified by the like numerals. The pattern plates may be made of wood, metal or other suitable material and the raised design provided thereon in known manner.

Since various modifications and changes may be made in the invention Without departing from the spirit or scope thereof, it is not intended that it shall be limited to the herein described specific embodiments thereof but only as is required by the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for government purposes without the payment of any royalties thereon or therefor.

What is claimed is:

l. A pattern plate for molding foundry pouring forms having a split pool runner fed between the pools, said pattern plate having attached to a broad face thereof a system of bosses of generally rectangular cross-section having the edges of their upper face rounded off, said system of bosses including a main boss having a section of lesser height defining a neck portion connecting an adjacent pair of twin upstanding sections, said main boss having attached thereto along one side thereof in even number on its twin upstanding sections and extending laterally therefrom in parallelism and equi-spaced relationship to each other, an even multiple, numbering at least four, of smaller bosses of equal cross-sectional area and lesser heighth and cross-sectional area than said neck portion, said smaller bosses being so arranged that said neck portion, in the horizontal plane, lies centrally between the innermost pair thereof and the sum of the cross-sectional areas of said smaller bosses being at least twice that of said neck portion.

2. A pattern plate as defined in claim 1, wherein the sum of the cross-sectional areas of said smaller bosses is twice that of said neck portion.

3. A pattern for the molding of foundry pouringforms having a split pool runner fed between 1e pools, said pattern comprising a system of bars. of generally rectangular cross-section having their upper faces flat and lying in a common plane and their lower faces rounded oil at the edges, said system including a main bar having a section. of lesser depth forming a neck portion connecting an adjacent pair of twin depending sections, said main bar having attached thereto along one side thereof in even number on its twin depending sections and extending laterally therefrom in parallelism and equi-spaced relationship to each other, an even multiple, numbering at least four, of smaller bars of equal cross-sectional area and lesser depth and cross-sectional area than said neck portion, said smaller bars being so arranged that said neck portion, in the horizontal plane, lies centrally between the innermost pair thereof and the sum of the cross-sectional areas of said smaller bars being at least twice that of said neck portion. 1

4. A pattern as defined in claim 3, wherein the sum of the cross-sectional areas of said smaller bars is'twice that of said neck portion.

WILLIAM H. JOHNSON.

REFERENCES, CITED The following references are of record in the OTHER REFERENCES The Foundry, October 1848, pages 68-13, inclusive, and 252.

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