US1552064A

US1552064A - Method of and apparatus for molding concrete

Info

Publication number: US1552064A
Application number: US435697A
Authority: US
Inventors: Lake Simon
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-01-07
Filing date: 1921-01-07
Publication date: 1925-09-01
Anticipated expiration: 1942-09-01

Description

S. LAKE Sept. 1, 1925.

METHOD OF AND APPARATUS FOR MO LDING CONCRETE Filed Jan. '7, 1921 connection Patented Sept. l, 1925.

UNITED STATES SIMON LAKE, or MTLFoRD, CONNECTICUT.

METHOD OIF-AND APPARATUS FOR MOLDING CONCRETE.

Application led January 7, 1921. Serial' No. 435,697.

To all whom t may concern.'

Be it known that I, SIMON LAKE, a citizen of the United States, residing at Milford, in the county of New Haven and State of Connecticut, have invented a certain new and useful Improvement in Methods of and Apparatus for Molding Concrete, of which the following is a full, clear, and exact description.

This invention relates to a. method of and apparatus for molding hollow Concrete bodies.

The object of the invention is to provide a hollow concrete body of greater strength and density of texture than it has heretofore been possible to produce with the use of known methods and apparatus, and to so speed up production by artificial seasoning of the concrete as to materially lessen the cost of manufacture and equipment, the repeated use of forms bengconscquently cxpedited. The invention also contemplates the impregnating and insulating of concrete bodies such as structural elements for building purposes, to the end that such elements may form structures practically impervious to moisture and heat and cold, and of such nature as to render them as nearly as possible non-transmitters of sound.

The invention consists in a. method of and apparatus for forming hollow concrete bodies having the characteristics above recited, wherein the body in Course of molding is subjected to great internal pressure by means of a partlally Collapsible expansible core adapted to be positioned in a mold and Surrounded with concrete and thereafter eX- panded by air pressure so as to compact the Concrete in the mold and express therefrom through porous mold-boards, assembled .in

preferably with the top and bottom of the mold, all air and surplus moisture contained in the concrete mixture, whereby a uniform density and homogeneous texture is imparted to the concrete and voids caused by trapped air and un- Combined moisture done away with. After the pressure caused by the air admitted to the core has so expressed all air and surplus moisture, steam is admitted to the core, whereby further expansion is produced and heat applied for the double purpose, respectivel of further densifying the concrete an drying it, and fusing the coating of properly of waterproof material with which the Core as I will hereinafter explainy andiinally claim.

In the accompanying drawings illustratl ing the invention, which like parts are similarly designated, Figure 1 is a Central, longitudinal, vertical section showing the apparatus of my invention with a concrete body being cast therein. Fig. 2 is a transverse vertical section taken on the line 2-2 of Fig-1. Fig. 3 is a section taken on the line 3 3 of Fig. 1 and showing the core and reinforcing members in position, but omitting the concrete.

It Will be understood that various forms of apparatus may be substituted for those herein shown, except as hereinafter claimed, but as a suitable apparatus for the purpose consisting of a form Composed of a frame,

respectively,

side and end members 1 and 2, preferably formed in one piece and of any desired material, and provided with fianges 3, to which the top 4 and bot-tom 5 are secured in any suitable manner, as by a in the several figures ofcarrying out my method, I show v plurality of bolts 6. The top and bottom are reinforced by means of transverse bars 7 so as to increase the resistance of same to internal pressure.

Interposed between the flangesv 3 and the top 4 and bottom 5 are mold-boards 8 and 9, respectively, formed of some porous material, for a purpose hereinafter appearing. I have found that balsa wood is suitable for these boards.

Adapted to be positioned within the mold is a core 10, preferably formed ofv sheet metal of such thinness as to give the core the proper resiliency for its purpose, as will later appear, and this core is provided at its ends with connection members 11 forming screw-connections for pipes 12 through which air and steam may be introduced to the interior of the core, control of same being provided for by means of

members

14 and 15 may be used, same being so supported within the mold as to be ca1l pable of withdrawal 'therefrom when the mold is lifted o of the finished molded body. y'

If desired, suitable reinforcement may be cast into the body, and I have shown such reinforcement as consisting of a plurality of longitudinally extending rods 16, of such number as to give the required strength, these rods being contained Within a tubular reinforcing member of Wire mesh, or expanded metal, indicated at 17. Transverse rods 18 may also be cast Within the body, these rods being capable of withdrawal after the cast body 1s finished, to leave openings transversely through the element for construction purposes.

When relnforcement, as shown, 1s used in casting the concrete body, I prefer to pro-AV vide the bottom mold-board 9 with supporting members 19 to correctly\position the reinforcement with respect to the bottom of the mold and thereby maintain it in proper position within the body of concrete during the molding operation.

20 indicates a layer of semi-fusible insulating material, adapted to increase the imperviousness of the concrete body and to bond therewith as will be hereinafter described.

In molding hollow concrete bodies according to my method, I prefer to proceed as follows The body of the mold, comprising the side and end members 1 and 2, respectively, is set up upon and bolted to the bottom 5, with the mold board 9 secured therebetween. Into this mold is poured enough concrete to reach approximately the level to which the bottom of the core will extend. Then the core with the surrounding reinforcing members will be forced down into this concrete until the reinforcing members rest upon the members 19, the bottom of the core being slightly pressed into the surface of the concrete. This pressure will to a certain extent collapse the bottom of the core, as indicated in dotted lines in Figs. l and 2. With the core thus in position, fusible inv sulating material in plastic form is poured around the core to form the layer 20. After pouring in this plastic insulating material, the mold is filled to the top with concrete, the weight of same being sufficient to partially collapse the top of the core and to hold the bottom thereof partially collapsed, also as indicated in dotted lines in Figs. 1 and 2. Then the upper mold board and the cover 4 are bolted in place and compressed air is turned into the core through one of the valves 13, the other of said valves remaining y closed. Sufficient air pressure will be introduced into the core to cause its collapsed top and bottom to distend, thereby imparting ,considerable pressure to the surrounding concrete. It is well known that in nearlylall mixtures of concrete there is considerable trapped air, and cement which has not been completely hydrated, also that there is considerable uncombined water present. The distending of the core, and the pressure upon the concrete thereby obtained, is sufficient to densify the texture of the concrete and to cause the cement therein contained which has not been completely hydrated to combine With the free water, and also to force out of the concrete mixture through the porous mold boards 8 and 9 all trapped air and surplus moisture. When this pressure in the core has been maintained for such a period as to have accomplished the desired result, evidence thereof being observable in the cessation of bubbling or seepage at the edge of the mold boards, the air pressure will be relieved from the core by opening the previously closed valve 13, so that the vair may escape.

Before the core 10 is placed in the mold, it is coated with a substance which is fusible under known temperature and pressure. For this coating I have found bitumastic, pitch, asphaltum, paraiin, or any one of these substances mixed, if desired, with sawdust or with ground cork suitable.

After the air has been allowed to escape from the core, the escape valve 13 is allowed to remain open and the core is connected with a source of supply of steam. Steam is then allowed tocirculate through the core at a moderate rate, so as to gradually warm up the surrounding concrete and further asslst in its complete hydration and hasten its drying. After the entire body of concrete has become evenly, or substantially evenly, warmed, the valve 13 is closed and the steam pressure in the core is increased until the core is still further expanded and its coating fused and driven or forced into the surrounding concrete, thus waterproofing it and filling all of thevpores. This steam heating of the body of concrete also serves to partially fuse the layer of insulating material 20 and cause it to bond with the concrete.

After a sufficient time has elapsed to have completely accomplished the desired result, the steam is shut o, the pipes 12 unscrewcd and removed', the bottom of the mold unbolted, and the mold slipped off of the cast concrete body. The external dimensions of the core having been reduced by the fusing of its coating, the core may then be easily withdrawn.

I-Iereinabove I have referred to the transverse rods 18 as being removable, and in order that this removal may be easily accomplished, I coat the rods 18, before their insertion, with a fusible compound such as is used for coating the core. The heat' of the steam in the core may be sufficient to fuse the coating of these rods, but if it is not,-

'nuance they may be heated by assing an electric current through them, an their coating thus and core, hollow columns and the like structural elements may be readily molded.

The invention lends itself also to a marked degree to the castin of designs upon concrete bodies, such esigns being either in relief or in intaglio, the only change necessary in the a paratus being the substitution in the mo d of plates or boards bearing the desired designs instead of the plain mold boards shown.

The rapid 'drying and waterproofing of f the concrete also tend to lengthen the life sco e of the following claims.

of the metallic reinforcing members, because no free moisture remains .in the iinished casting, and no water can later enter it to corrode them.

It is to be understood that I do not consider my invention as limited to the particular method herein recited, nor to the particular apparatus herein shown and described, except as hereinafter claimed, various changes in the mode ofl procedure of molding, and inthe arrangement and construction of the apparatus, being possible within the spiritof the 'invention and the 1. A method' of molding hollow concrete bodies, which comprises subjecting such bodies to internal pressure and heat and the action of a waterproofing material.

2. A method of molding concrete bodies, which comprises filling a mold provided with porous walls with concrete surrounding a hollow core, and introducing pressure to theinterior of said coreto drive oif air and moisture from said concrete through said porous walls.

3. A method of molding hollow concrete' bodies, which comprises filling a mold with concrete surrounding a coated expansible core, applying air pressure to the core to compress the concrete, and then lapplying steam pressure to thel core to fuse the coating thereof and force it into the concrete.

4. A method of forming hollow concrete bodies, which comprises partially filling a mold with concrete, placlng yin said mold upon said concrete an expensible core, placing around said core and upon said concrete an insulating material, Acompleting the filling of said mold with concrete, and applying heat and pressure to the interior of said core to expend same and compress and dry said concrete and bond it with said insulating material. y v

5. A method of`molding hollow concrete bodies, which comprises partially :filling a mold with concrete, placing within said mold a partially collapsible hollow core, completin the filling of said mold with concrete t e weight whereof will partially collapse the core, and applying pressure to the interior of said core to expand same and .compress said concrete.

6. A method of molding hollow concrete bodies, which comprises partially filling a 'mold with concrete, placing within said mold a partially collapsible hollow core coated with a fusible Waterproofing material, completin the lilling of said. mold with concrete t e weight whereof w1ll partially collapse the core, and applying pressure and heat to the interior of said core to expand same and compress said concrete and fuse said coating and force same into said concrete.

7. In an apparatus for molding hollow concrete bodies, a mold provided with porous members and adapted to receive a concrete mixture, and an expansible core adapted to be positioned' within said mold and to be expanded therein to express airl and excess moisture from said concrete through said porous members.

'8. In an apparatus for molding hollow` concrete bodies, a mold,a'top and a bottom therefor provided with porous members, and a partially collapsible expansible core adapted to be positioned within said mold, for the purpose specified.

In testimony whereof I have hereunto set myhand this 6th day of January /A. D. 1921. I

sIMoN LAKE.