US2440754A - Method and apparatus for producing concrete beams - Google Patents

Description

A May 4, 1948.

METHOD AND APPARATUS FOR PRODUCING CONCRETE BEAMS Filed Sept. 11, 1946 on m E. NAGEL 2,440,754

6 Sheds-Sheet 1 A IN V EN TOR.

' George E Nqge/ W AW v ML ATTORNEYS May 4, 1948. NAGEL I 2,440,754

ND APPARATUS FOR PRODUCING CONCRETE BEAMS Filed Sept. 11, 1946 5 Sheets-Sheet 2 I N VEN TOR.

ATTURNEY y 1948- e. E. NAGEL 2,440,754

METHOD AND APPARATUS FOR PRODUC ING CONCRETE BEAMS Fild Sept. 11, 1946 v e Sheets-Sheet 5 11 INVZI-LNTOR. I 3 Fi l o o, o 3; Y GewyeE/Vqgel ATTORNEYS y 1948. G. E. NAGEL 2,440,754

METHOD AND APPARATUS FOR PRODUCING CONCRETE BEAMS Filed Sept. 11, 1946 6 Sheets-Sheet 4 INVENTOR. Gew ge E Nagel A T TORNEYS May 4, 1948. v e. E. NAGEL METHOD AND y 4, 1948- G. E. NAGEL 2, 40,754

METHOD AND APPARATUS FOR PRODUCING CONCRETE BEAMS 7 Filed Sept; 11, 1945 6 Sheets$heet 6 v final llll lh l ildw l lllllll lllllllF I N VEN TOR. George E N09 I4/;l////////I////////////////////////////////////////////////////////// ////l ///l ATTORNEY? Patented May 4, 1948 UNITED STATESVPATENT OFFICE:

METHOD AND APPARATUS FOR PRODUCING CONCRETE BEAMS George E. Nagel, Columbus, Ohio Application September 11, 1946, Serial No. 696,106

7 Claims. 1

My invention relates to method and apparatus i Cored concrete beams have been provided in the prior art and have been used in floor and roof constructions. These beams are usually provided with a plurality of cores extending therethrough. The cores are used as channels:

for pipes, electric conduits, etc. The prior art beams with which I am familiar are of non-symmetrical or rectangular cross-section and, in addition, usually have heavy metal reinforcing tension rods in one of the wide faces only of the beam which is to be lowermost and is to form the tension face of the beam. As a result, when the beam is set into the structure it must be set with its wider faces forming its top and bottom sides and with the face, thathas the reinforcing tension rods embedded therein, lowermost. In incorporating this type of concrete beam in a. floor or similar structure, a series of the beams are placed side-by-side, the upper surfaces serving as a floor or sub-floor surface and the lower surfaces serving as a ceiling surface to which plaster may be applied. It is desirable for the upper and lower surfaces of the beams to be provided withdovetail grooves to permit keying ofa mastic floor surfacing material or a mastic ceiling material to the respective surfaces. It is also desirable to provide similar grooves on the side surfaces of the beams so that adjacent beams may be keyed together with grout or similar material that is poured therebetween so that all the beams will be tied together and will function as a single beam. In the past, it has not been possible to provide such dovetail grooves in the various surfaces, due to the methods used in producing such beams, although grooves have been formed in the side surfaces of prior art beams but these grooves have not been of the dovetail or undercut type because they i could not be formed with prior art molding operations.

Due to the necessity of. forming the cores in the concrete beams, casting or molding methods have been used in the prior art which are very complicated and inefficient, and which require complicated and cumbersome apparatus and considerable manipulation thereof. One method has employed inflatable tubes which must beheld in a predetermined exact relationship with respect to the metal reinforcement and with respect to the sides of the form inywhich the concrete is cast.

2 According to this method, the outer surfaces of the beam are formed by the rigid walls of the mold or form and, therefore, it has been impossible to form dovetail or undercut grooves in such surfaces, inasmuch as such formations would prevent removal of the forms or molds from the cast beams.

Que of the objects of my invention is to provide a, method and apparatus for producing a cored concretebeam whichis of symmetrical or uniform cross-section and which has the metal reinforcing uniformly distributed therein so that the beam may be positioned in the structure with any side up and will still function properly as a beam.

Another object of my invention is to provide a method and apparatus for producing a concrete beam which has dovetail or undercut grooves formed on all of its longitudinally extending outer surfaces to provide proper keys for floor surfacing or ceiling surfacing materials and proper keys for tying together adjacent beams of a structure.

Another object of my invention is; to provide a simple, effective and economical method for forming cast concrete beams of the type indicated above.

Another object of my invention is to provide a method which is of such a nature that simple apparatus which can be manipulated easily can be employed in performing the method,

Another object of my invention is to provide simple, rugged, efficient and easily operable apparatus which can be built at a relatively low cost and can be operated economically for producing cast cored concrete beams of the type indicated.

Another object of my invention is to provide a method of producing cored concrete beams, wherein the core can be produced easily durin a simple casting operation without theuse of core forms which are diflicult to positionin the mold before the casting operation and to remove therefrom after the casting operation.

Another object of my invention is to provide a method of forming concrete beams whereby undercut or dovetailgrooves may be produced in the surfaces of the beams without interfering with the removal of thelmolds'or forms therefrom.

Still another object of my invention is to provide a method of the type indicated in the preceding paragraph whereby any. desired confi ur-ation or arrangement of the grooves may be obtained.

According to my invention, the beam produced fi strq a ede the centrifugal T 11 3 is an elongated. cast or molded concrete beam. It preferably is of substantially square cross-section with a core of circular cross-section centrally located at the axis thereof and preferably extending for the full length thereof. Longitudinally extending metal reinforcing is embedded in all sides of the beam and is uniformly arranged therein 1 so that regardless of iwhich side of. the beam is in contact With'the supports at its-ends, the beam will function properly in a manner similar to an I-beam. Furthermore, all side surfaces of the beam are uniformly provided with dovetail or undercut grooves so that lgeyihggrooves are provided on all surfaces where needed.

The method which I employ for producing the beams is a centrifugal casting ormpldingmethod. I provide an elongated mold or form of asize and shape proper for forming a beam. The mold consists of a lower pallet and an upper cover, both of which-are formed-of angle-.iron.andlwhichwhen combined form a boX-like.: formi. orimoldlfor... the beam; A lining for the wall of the .moldtis Sprovided-andthis lining is of fiexiblelmate'riaLs'uch as rubb'er. fTh-is linir fg is ir1theiorm of .aLmat which I has projections on the surface thereof, which Will be innermost in the mold, that. will serve to produce'thedovetail grooves in theicast b'ea'm.--- 1.

flexible lining is placed; on the pallet, which is -or 'V'-shape--'ro'ss-seetien and sei ves as a trough for receiving the concretewith 'the lining hang- "ing aconsiderabledistance-ever -bothisides thereof. The metal reinforcing, in the form of a Wire page is"placed in the' pallet on the 'linirig.--' A predetermined.- weight. or suitable :eonerete' 'm-ix "is Y then iaceqgm-the"pai etgpeingqpoured through the reinforcing on the pallet, an

ge ahd ontothe' lining' resting ly pallet. Means is p Vldd at ach end of'the mold pallet for"losihgthe moId'with the egic 'eption or at acentrally di posed opening ofan 'ar'a correspending to the area ofthe core op'jning' to be ibrmdfe ih *e e eid t e n w closing means isaS'truGture-fOr exeitin 'n axial cen i u a. L; bout its long'i n s slgvvlyand thickn s leav n th eene ete ,ue ierfiflr 5 *tributed to thevarious sides and with a-core therein of predetermined diameter. The mold the a tateavalseemaedaha the stributed 'along the stribute the lifter-l the "spinning pr 'o'eess is completed, the

'mold box is removed froml'the cage. The cover section is removed and the lower mold section which serves as a pallet for carrying the beam .nenbauseiin trans the beam to the room where it is' cured while the reinforcing stilbmaintained under tension. Then it is removed from-the pallet. The rubber lining may again be; casting operation. Rubber linings having various designs and configurations of ridges therein may be employed in the mold to obtain various arrangements of the grooves in the 0 surfacesofthebeam...

Theffor'egoing and.-.ot.her: objects, and .advan- 1 tages of .the: present ihventiongwill. a pearfrom the, following ldescripjtioniand 1 al mendeclv claims when: consideredin;.connection with. the accompanying drawings forming a part Qfgthespecifica- .tion wherein like reference. characters designate corresponding, parts in the Tseveral views and whereinzu. an. -...-F.igur e l is a diagrammaticzplan Jilfl Lof vap- 'paratu's which I' preferablyuse for performing my method, .1 l

Figure 2. is a :s-ide. elevational 'view' of the 'apparatusshowninl igure 1. v, i ..Figure-.3-. is .alitransverse sectional view; taken along line '.T3 of Figurel. N

l vI FigurelA .isQLa a transverse sectional view taken along.line 4-.-.;-4.ofEigure1.... m- .iFigureJ 5.21s: a :side;. elevational. .view. f of the .-centrifu'gali casting machine of .'my appara'tus and 40 the associatedzmoldereceivingicradle..

l figurefi is. a; plan view ofth structure shown 'inFigure-aa J a I :.-F.'igure 7 is.a p'ers'pective view-partly. out away, of J the pallet and c'ooper'ating -cover Iof "the mold illustrating the flexible 'm'old' lining in" -position t re Figure 8 is a rari'sverse secti'n'al view taken substantia'llyialohg line 8-1-3 ofFigure' 5, showing the palletof 'the imold withltnerubberlining and ibeam reinforcing-ptisitioned'therein.

Figure 9 iszaview' similar jtoFigiireB, but show 'ing the concrete'beingT- po'ured Ti'ntoj the mold. .-.:.Figure 10 Eiszia similar. viewsho'w i'ng the" flexible lin'irigiwithits sides'folded iipiso that the adjacent edges overlap; re'ady' for themold pallet to L receive thel'coveij. e 1-; Figure llijis a 'im'i'lar view showingthcover positioned ontli etand the more ready for the 'castingopera 1on0 1 1 r Figure -12'is a longitudihal sectiohal view taken substantiallyalohg fline"I 2 l 2 "of Figure "11 illustratih'g tensioni'ng -meanslassdciatd with the mold "forfltnSionlihg'i'the reinforcing rods""befo're the castingo'fierati6nu s li'igure l3 i's'a rid view of thest'ruc'ture' shown measure- 12.;- ti aFigure" l4 i's atiansverse 'sec iorial' view taken receivi'n "'g'e of theentrifugal' castingmachine.

F-igu re IS' is a side elevatio'na'l view of the strucis in before the cage is rotated.

showihg thezmoid .po tionedlin lthem'ola receivr .5 Figure 17 is a view similar to Figure lfi, but showing howthe concrete has been uniformly distributed in the mold by the rotation of the cage.

. Figure 18 is a perspective view of a section of a cored beam producedby my method and appaan arrangement of dovetail grooves also produced by the lining of Figure 22 which is positioned diiferently in the mold to produce this different arrangement of the grooves.

Figure 22 is a plan view of the lining used in producing the dovetail grooves in the beams of Figures 20 and 21.

Figure 23 is aplan view of another typeof lining used in producing another arrangement of dovetail grooves in the surfaces of the beam.

Figure 24 is a plan view showing a number of cored beams produced according to my invention incorporated in a floor construction, the cored beams being used as the radiators of a heatin system.

Figure 25 is atransverse sectional view taken along line 25-25 through several of the beams and illustrating how adjacent beams may be secured together.

Before explaining in detailthe present invention, it is to beunderstood that the invention is not limited in its application to the details of construction and arrangement of' parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. It is to beunderstood also that the phraseology or terminology employed herein is for the purpose of description and not of limitation. e I

InFigures 1 to 4, inclusive, I have illustrated the apparatus which I preferably employ in carrying out my process. The apparatus comprises an elongated and downwardly inclinedconveyer I. This conveyer includes a frame which supports on its upperside a pluralityof longitudinally spaced pairs of rollers 2. The rollers of each pair are arranged in V relationshipso as to form a cradlef'or receivin'gthe pallet 3 of the mold which is used in forming the concrete beam. This pallet 3 is in. the form of'an angle iron of suitable size to formtwo-sides of the beam. The

rollers 2 of each pairare of -propersize and are properly spacedso that the pallet will rest thereon in the manner indicated in Figure 3. The rollers 2 may be replaced with different size rollers and are preferably adjustable relative to each other,

so as to receive different slze pallets;

The pallet is depositedbya crane on the upper end of the conveyer I, that is, the left hand end of Figure 1 atthe station A. The pallet is pushed along the conveyer, aided by. gravity, to the station B where itreceives the flexible mold lining 4.. This mold lining is preferably maderof rubber and is indicated best in Figures8 to 11. It has, formed on its inner surface, alternating ribs and grooves 6. The ribs 5 are of dovetail crosssection so as to produce dovetail groove-sin the side surfaces of the beam tobe formed in the mold. The lining 4 is placed On the pallet in the extent.

The pallet with the rubber lining therein is now shoved to the station C at the lower end of the conveyer I. At this station, it receives the metal reinforcing. The metal reinforcing is in the form of a cage I extending substantially the full length of the pallet. This cage is illustrated best in Figures 8 to 13. It includes the longitudinally extending tensile rods 8 which are held in spaced relationship by means of the square transversely disposed wire members ,9 which are disposed at longitudinally spaced intervals.

While the pallet is at the station C, the reinforcing is pretensioned, and is centered on the pallet. As shown in Figures 12 and 13, the means for pretensioning the longitudinal members 8 of the reinforcing comprises a unit Iil which. cooperates with a closure member I I,for the end of the mold. The same arrangement is provided at each end of the mold. To pretension the reinforcing members 8, the end closures III of the mold are mounted on the pallet 3, as shown best in Figure 12. It will be noted that the ends of reinforcing rods 8 extend beyond the ends of the mold pallet and themold closures I I are'provided with openings I2 to permit slipping of the closure members over the reinforcing rods 8 into mold closing position.

When the closures H are mounted on the ends of the reinforcing cage 1 and on therends of the mold pallet, they serve to center the cage within the mold pallet so that it will be spacedfrom the sides thereof. It will be noted that each member II is provided with a reduced inner square portion I3 which fits within the end of the mold pallet to properly locate it relative thereto. Thus, there is a shoulder I4.provided on member II, which abuts the end of the mold pallet. A large opening I5 is provided at the center of each closure Ii to permit the escape of water from the ends of the mold. The tensioning unit It is similar in shape to the closure I I and is provided with a series of openings I6 which receive the projecting ends of members 8. Set screws ,Il threaded outwardly from the large central opening I8 of unit It into the openings l6 anchor the unit It to the rods 8 when desired. Longitudinally extending bolts I9 are threaded through unit I 0 and engage the outer face of closure II. The set screws I! are first tightened before the bolts I9 are tightened. The bolts I9 of each unit II) are so located (Figure 13) that all three of them will be located below the center line of the mold pallet 3 so that when they are tightened uniformly the member I0 will not tilt laterally. It will be apparent that tightening the bolts I9 will move the members I8 outwardly away from members II. Consequently, this will pretension the rods 8, including the uppermost rod. I

From the station C, the pallet 3, with the lining 4 and cage I in position therein, is shoved onto a pallet-receiving cradle formed on a transversely movable carriage 20. The pallet-receiving cradle is formed by pairs of longitudinally spaced rollers 2a which are like the rollers 2 and are supported on the carriage 28 in the same manner that the rollers 2 are supported on the conveyer I. The end of the. pallet-receiving cradle on the carriage 2B which is adjacent the lowermost end of the conveyer I is at substanstantially the same height as such end of the conveyer I. The opposite end of the carriage is at a lower level. In other words, the carriage moisture inwardly into the coreop ning; as shown in Figure 17, so that it can drain from the ends of the mold through the central openings l in the closures II. The outer surfaces of the concrete unit are compactedagainst the mold lining 4 which will thuseform the dovetail grooves therein. .7 V V After the spinning operation, the bolts 43, carried by the cage 38, are loosened, permitting the remova1 of the mold from the cage by pushing it onthe rollers 4i and outer the opposite nd of the cage. Movement oflthe mold from the cage 38 may be aided by a chaini33a (Figure 1), similar to chain 33, whichextends beneath the cage 38 and is driven, when desired, by a suitable motor. This chain33a extends beneath'a con veyer lb which is of the same structure as the conveyer la. When the mold reaches the station F where it is completely on the conveyer ID, the cover- 35 is removed/while-the'units HI and ii are still kept in position on the ends of the pallet to maintain tension on the rods 8. The pallet 3 with the finished concrete beam carried thereby may then be transported by a crane to the curing room. At the curing room, the beam is cured while the rods 8 are still maintained under tension. Then the units I0 and H are removed from the pallet and the beam is removed from the pallet. The pallet and the units l0 and H may now be used over again. Also, the rubber lining 4 is stripped from the surfaces of the concretev beam and can be used over again.

Cast concrete beams of the type shown in Figures 13, 20 and 21 are produced by the method described above. As shown in Figure 18, the beam 55 will be of square cross-section with all of its walls uniform and with the concrete distributed uniformly in each side wall. The core 56 will extend the full length of the beam, will be axially disposed and will be of circular outline. The undercut or dovetail grooves 51 will be formed in each side surface of the beam. For example, the grooves in the beam 55 of Figure ill will be formed by a rubber mat or lining 4a of the type shown in Figure 19. The rubber lining can be stripped from the beam after the concrete sets sufliciently without disturbing the grooves formed therein due to the yieldable nature of the lining. The reinforcing will be uniformly distributed in the side walls of the beam. Thus, because of the uniform nature of the beam, it may be used with any of its sides down in a floor or roof structure.

The type of groove and the arrangement of the grooves formed in the surfaces of the beam may be selected by selecting a suitable rubber lining. For example, grooves of the type formed on the beam 55a of Figure 20 may be produced with a rubber mat of the type shown in Figure 22. Also, grooves of the type formed on the beam 551) of Figure 21 may be formed by the rubber lining of Figure 22 which is positioned in the mold differently than when used for forming the beam 550.. In the position necessary to form beam 550., the lining will be so positioned that the corners of the compartment formed by the lining corresponding to the corners of the mold, will be along the dotted lines a of Figure 22. In the'position necessary to form beam 55b, the corners will be along the broken lines D. Figure 23 shows another type of lining which can be used for producing a different arrangement of th grooves.

In Figures 24 and 25, I show an example of an installation of my beams in a floor construction. The beams 55 are disposed in side-by-side relationship. To secure all the beams together so thatthey function as a single beam, it is merely necessary-to pour grout in the spaces between adiacent'beams, as indicated in Figure 25 by the I numeral 58, which will harden and'form keys that cooperate'with the dovetail grooves 51 to secure the beams together. The grooves 51 will also. serve as keying means for the ceiling surfacing material 59 and for similar floor surfacing ma terial.; H In the construction shown in Figures 24 and 25, the beams are used as the radiators of a heating system; The cores of the beams will serve as passageways for the hot air. In the example shown in Figure 24, two adjacent beams are connected together at one end, theopposite end of one beam being connected to an inlet duct and the corresponding end of the other beam being connected to a return duct. Variations of this system'may be'made. ..i 1" :1; lt willbe apparent from the abovedescription that'I have provided a method and apparatus for producing cored concrete beams which is simple, economical and efl'ective. The use of core-forming members has been rendered unnecessary by my novel method and apparatus.

Various other advantages will be apparent from the preceding description, the drawings and the following claims.

Having thus described my claim is:

l. The method of casting a concrete beam of square cross-section with an axial core therein which comprises placing on a pallet composed of an angle member, a sheet of rubber which covers both sides of the pallet and hangs over the edges thereof, depositing a measured quantity of concrete in said pallet on said rubber sheet along the length of the pallet, folding said rubber sheet upwardly until its edges overlap and form a continuous chamber for the concrete, placing a cover of the same size and shape as the pallet on the pallet to form a complete mold, the rubber sheet completely lining the two sides of the cover, closing the ends of said mold with the exception of a central opening in at least one end of the mold to permit drainage of moisture, and then spinning the mold about its axis to distribute and compact the concrete in the mold.

2. A method according to claim 1 wherein the rubber sheet has projections thereon which are wider at their outer sides than at their bases and will form undercut keying sockets in the surfaces of the concrete beam.

3. A method according to claim 1 wherein a reinforcing cage'of square cross-section is placed on the pallet before the concrete is deposited therein, said reinforcing cage including longitudinal tensile members, said members being placed under tension after the' mold is closed and before the spinning operation.

4. A method according to claim 1 wherein the mold is first spun at a low speed to distribute the invention, what I concrete in the mold and form the axial core and is then spun at a high speed to compact the concrete and squeeze the moisture into the core from whence it is drained.

5. A method according to claim 1 wherein the cover of the mold is removed leaving the beam supported on the pallet for transportation to a curing room where it is removed from the pallet.

6. Apparatus for casting a concrete beam of square cross-section comprising an elongated mold formed of two cooperating sections of an angle iron, a conveyer for receiving one of said

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