US1416927A

US1416927A - Apparatus for molding hollow bodies

Info

Publication number: US1416927A
Application number: US439184A
Authority: US
Inventors: Percy A E Armstrong
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-01-22
Filing date: 1921-01-22
Publication date: 1922-05-23
Anticipated expiration: 1939-05-23

Description

P. A. E. ARMSTRONG.

APPARATUS FOR MOLDING HOLLOW BODIES,-

APPLICATION FILED JAN- 22, I921.

Lfi A Patented May 23, 1922;, 72W 725' PEURGY A. E. ARMSTRONG, 01F LOUDONVILLE, NEW YORK.

APPARATUS FOR MOLDING HQ-LLOW BODIES.

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Application filed January 22, 1921.

, have invented'certain new and useful Tmprovements in Apparatus for Molding Hollow Bodies, of which the following is a' specification.

My invention relates to apparatus for making cast hollow bodies, such as pipes, columns, hollow ingots and the like. The present invention is concerned with the cores used in making hollow castings. v

In proceeding'in accordancewith my invention, the core is preferably arranged upon a rod or tube preferably of metal, and the core is preferably made up in a plurality of rings or sections, having openings therein for the passage of the rod or tube whereby the core portions are positioned, preferably centered, directly on the tube or rod. The core sections are preferably all of like form, so that a single pattern will serve for mak ing all the core sections, and the core sections are so constructed that while they are supported with ample strength and firmness and give ample support to the metal of the casting while molten and in the preliminary stages of solidification, they give way as soon as any substantial shrinking or other stresses are imposed, permitting the whole casting to solidify naturally without hindrance and in the manner best suited to its particular composition and free from any tendency to formation of cracks or the like.

Tmsecure this and related results the'core sections are preferably made of molding sand'provided with interior portions of re duced density, as for example they may con- .tain air spaces or spaces filled or partially filled with light porous materials, so that they canreadily give way as when shrinking of the hollow'c'asting takes place, leaving the same to shrink freely and naturally as if the core had been removed, the extra spaces provided within the core sections being suflicient to provide ample room for all the broken down material of the core sections as the casting shrinks. This broken'down material can be readily removed when the hollow casting has Specification of Letters Patent.

of Great Patented May 23, Serial No. 439,184.

or 1n equivalent ways.

W1th the foregoing and related objects in v ew, my invention consists in the combinations and apparatus herein described and claimed.

In the drawings showing preferred forms of apparatus, Fig. 1 is a longitudinal-sect1ona1 View of a mold and core having a perforated tubular core center, and Figs. 2-5 are fragmentary views similar to Fig. 1 but showing modified forms of core sect1ons arranged upon a rod instead of a tube.

Reference character 10 designates a tubu-- lar core center having gas vent holes 11. The

mold core sections

12, 12 may be of var ous materials, but are preferably oil-sand cores made from the same pattern and baked. In the form shown in Fig. 1 core sections 12 are preferably cylindrical but maybe of varlous cross-sectional forms as desired, and may be conveniently described as being substantlally of inverted cup form, having side walls 13 and a base or head 14. The portion 14 is provided with an opening 15, adapted to fit on the central tube 10 and to center the mold sections thereon.

The mold of Fig. 1 is arranged for top pouring and comprises an outer mold member 16 in a box or other support 17 and having a bore 18 of substantially the form de sired to be'given to the exterior of the hollow casting which is to be made. The bottom mold member 19 fits into bore 18 and has an opening 20 for receiving and centering the tube 10, and-therefore the core sections 12 sleeved on tube 10, with respect to the bore 18 of the outer mold member 16; and the mold member 21 provided with opening 22 to fit totube 10 serves the like purpose at the upper end. Mold member 21 has an inlet opening 23 and a vent hole 24 which connect respectively with inlet opening 25 and vent hole 26 in the pouring piece 27, which-may likewise have an opening 28 to fit over the central tube 10.

For top pouring the

core mold sections

12, 12 may be arranged as inverted cups slipped upon the central tube 10, with the margins 13 resting respectively on the bottom of the mold and upon portion 14 of the solidified, as by blowing or washing it out,

next lower core mold section of the series. The joints are preferably luted or otherwise treated to give a smooth surface to the builtup core and thereby prevent formation of any seams or fins in the finished casting.

The core sections 12 shown in Fig. 1 are either hollow as shown at 12" forming an open space or recess for a part of the length of the section 12 adjacent to the pipe 10,

or the recesses therein are provided with a filling of porous material 12, and are adapted for giving the necessary initial support to the cast material and to break down upon application of shrinking or other stresses. The hollow bodies may be poured in casting in various ways, as for example, with the mold arranged horizontally as well as vertically. While the mold sections 12 of Fig. 1\ are best adapted for top pouring, they may be used where the position of the mold at pouring is other than vertical, as for example with the mold arranged horizontally.

The core sections 121 of Fig. 2 are of the same form as core sections 12, except that the margins 121 of each fit into a peripheral notch or cut-out 121 of the adjacent core section, thus centering each ring or section at one of its ends upon the adjacent core ring or section. The central supporting member in this case as well as in Figs. 3 to 5 is shown as a rod 10', but a tube or other form of supporting device may be used, if desired. The form of mold core section shown in Fig. 2 is well adapted for horizontal pouring as well as vertical pouring, the rod 10', which is made from metal or other material of high mechanical strength. serving to support as well as to center the core sections. When desired and especially where the core sections are not vented through the central supporting member, vent openings may be provided in the core sections, as at 130, or grooves may be provided for this purpose adjacent to the supporting member as shown at 131, Fig. 2.

In Fig. 3 the core sections 122 have stepped margins 122 fitting into the stepped peripheral notches or cutouts 122" of adjacent sections. In Fig. 4 the core sections 123 have

end closing portions

123 and 123 at their opposite ends, and the core sections are not nested together or centered at one end on one another, as in Figs. 2 and 3, but are centered and supported at both ends on the center rodlO.

In Fig. 5 the core sections 124 are provided with grooves 124; which serve to provide strengthening ribs on the interior of the pipe or other hollow casting. It will be observed that such strengthening ribs are but one example of internally projecting members or portions which may be formed in the hollow casting, and that hollow castings with any desired interior contour or formation can be produced in accordance with the present invention by reason of the cores breaking down during solidification of the casting and being removed in the broken down condition.

The interior of one of the mold core sections 12 is shown in Fig. 1 as being filled with porous material 12. such as shavings, excelsior or the like,'or non-coml ustible porous material may be used if desired, so long as the available spaces provided are sufiicient to give the necessary space for displaced core material when the castin shrinks. Such filling of porous material serves to give slightly added strength to the core sections during the first stages of casting, but may be dispensed with if desired.

By my invention I have successfully molded pipes of cast steel ten inches in diameter and fourteen feet in length in horizontally arranged molds, and hollow bodies of practically any size and dimension can be produced from practically any metal or composition which can be melted and poured. The cores are easil and quickly made and assembled and while they afford the adequate strength and support for the molten metal, are readily collapsed when any shrinking strains appear. The cast objects produced are clearly and accurately molded and no difiiculty is presented in removing the core material. lVhen desired the tube or bar on which the core rings or sections are fitted can be removed while the casting is still hot. permitting the core sand or other material to fall out of the pipe or other hollow body while still hot. thus simplifying the operation and permitting more rapid cooling of the hollow casting and reducing the time required for production. It is to be understood that the apparatus shown is for illustration only and that modifications and changes may be made within the scope of my claims.

I claim:

1. Apparatus for casting hollow bodies. comprising a mechanically strong core center and a plurality of collapsible mold core sections centered directly upon and supported by said member.

2. Apparatus for casting pipe. comprising a tube or rod. a plurality of mold core sections sleeved on said rod and centered and supported there-by. said core sections having recesses therein the walls whereof are spaced away from said center member to provide spaces to receive the sand of the core sections and permit same to collapse when subjected to shrinking or the like strains.

3. Apparatus for casting pipe. which comprises a -mechanically strong core center member and a plurality of hollow core rings sleeved thereon and making substantially a close fit therewith.

llO

Lara ear I 4. Apparatus for casting pipe, which comprises a tube or bar, a plurallty of recessed core sections centered and supported directly on said bar, each of said core' sections having a peripheral groove or cut-out for receiving a peripheral flange or lip upon the adjacent core sections.

5. Apparatus for making cored castings, which comprises a tube or rod for forming the center of the core, and a plurality of core sections sleeved thereon for a portion of their length and having internal recesses providing hollow spaces adjacent to the tube or rod for the remainder of their length.

6. A core for making the boresof hollow castings, which comprises a tube or rod, and a plurality of core rings of substantially cup shape, placed end to end, and

provided in their, bottoms with holes through which said tube or rod may pass, said tube or rod making substantially a close fit within said holes.

7. A core for making the bores of hollow castings, which comprises a tube or rod and a plurality of core rings of substantially cup shape, placed end to end, and provided withholes in their bottoms through which said tube or rod may pass with the core rings fitting around said tube or rod sub-u stantiall closely, and said core rings being provided with gas vents.

In testimony that I claim the foregoing, l have signed m name hereto.

ER-C A. E. ARMSTRONG.