Jan. 7, 1947. C. DOBELL 2,413,911 FABRICATION OF CONCRETE ELEMENTS 0R STRUCTURES Filed Oct. 13, 1943 3 Sheets-Sheet 1 Ir d I I I‘ INVENTOR CURZON ATTORNEYS 7 ' c, DOB-ELL FABRICATION 0F CONCRETE ELEMENTS 0R STRUCTURES Filed oé'tl 13, 1943 3 Sheets-Shoot ‘2 :1.‘ "an. II ./ l3 40 .@M?. . H.6_0.3: 71 .‘4 0 i|IV/rl. W.Avwm?.“g 4/. INVENTOR cunzcn ooBELL ' DY . ‘I'TORNEYS A. Jan. 7, 1947. 2,413,911 C. DOBELL FABRICATION 0F CONCRETE ELEI'IENTS OR STRUCTURES Filed Oct. 13. 1943 3 Sheets-Sheet 3 gmw 3, . if. n./i: . ?liywm.g§ Gr .3-.rv .¢...".t,...ri. : a 1.. 63 ... M ma “R1001 m Patented 1....‘1. V1941. 2,413,911 ‘PATENT orn‘ca * _’ v UNITED .s'rArEs 0R STRUCTURES‘ Curzon Dobell, NewYork, N. Y. ' _ Application October 13, 1943, Serial No.- 506,074 1 v, (or. 25-11) 19 Claims. This invention relates‘ to the fabrication ‘of 111811‘ .8. To provide for the fabrication of a high strength concrete elements or structures by a‘ strength concrete structure upon or against a ' preformed structure by a continuous process continuous process which has a wide range of use_' which. simpli?es the development of continuity ' ' . " The more important, objects of the invention to between the two structures. ' 9. To provide for the ‘fabrication of high may be summarized as follows: 1. To provide a continuous fabricating process‘ ' ' strength concrete elements or structures by a con tinuous process, which lends itself to the fabrics. whereby high strength concrete, elements or tion of solid, hollow, or cellular elements or struc structures of great length'or-height may be rap- , idly and economically fabricated. in situ or other 10 tures oi'ianv desired height, length, shape or cross wise, with the aid of relatively short moulds of 10. To provide for the fabrication of high comparatively simple and inexpensive design. 2. To provide for the building of high-strength ' strength concrete elements or structuresby an extrusion process in which pretensione'd and/or .concrete elements or structures in situ upon or ful application. section. - i against a preformed structure by a continuous 16 passive reinforcement members are progressively * process of fabrication which enables said me;1 formed structure to be economically used as part -_ of the construction apparatus. 3. To provide for the. fabrication of high strength concrete elements or structures by a. 20 continuousprocess which enables the strength of the concrete in successively formed sections of such elements ‘or structures to be selectively con ' trolled without changing the thickness or size of said sections. - ' embedded in the concrete during fabrication ‘ thereof. , . - . 11. To provide for the fabrication, in situ, of high strength concrete elements or structures of considerable height by a continuous process which may be carried out with the aid of relatively short‘ ' moulds or forms and with little or no scaffolding and in which provision'is made for incorporating‘ passive and/or pretensioned reinforcement mem 28 hers in the concrete during its passagethrough . the mould or moulds. 12. To provide for . the fabrication of high‘ strength concrete elements or structures by a continuous process in 'which the concrete is sub continuous process in which the concrete is forced jected to high pressure which is utilized toeifect rapid‘ removal of excess water from the concrete 30 through a mould vuncler‘a pressure which is de V 4. To provide for the fabrication of high strength'concrete elements or. structures by, a termined, at least in part, by controllable ten and thereby speed up the transformation of the‘ concrete from aplastic to a granular condition during passage of the concrete through a rela tively short mould or form. siOn produced in reinforcing members embedded 1‘ v in the concrete during its passage through the ' mould. - ' - .5. To provide for the fabrication of ‘high 35 " 13. To provide for the fabrication of high' ‘strength vconcrete elements or structures by a continuous process in which the concrete is forced under pressure through a mould and in which . water is‘qulckly expelled from the interior as _ the pressure of the concrete is utilized to stretch well as from outer portions of the mass in such manner as to ensure the rapid development of 40 and tension reinforcement members embedded in strength concrete elements or structures of great mass by a‘ continuous process in which excess uniform strength characteristics throughout the the,. concrete during its passage through said entire mass. mould. - - . . > > ‘ 6. To provide forthe fabrication, in situ, of 14. To provide for the fabrication of high high strength concrete elements or structures of - . strength concrete elements or structures by a ' considerable height by a continuous process 45 continuous process in which the concrete is forced which requires little or no scaffolding. 7. To provide for therapid, economical and ' convenient fabrication of concrete structures by under pressure through a mould and in which re inforcement members. pretensloned to a predeter 'mlned degree, are embedded in the concrete dur ing its passage through the mould, the maximum a process which enables ?oors. beams‘. roofs or other elements of a structure to be ‘first fabricated 60 extent to which the reinforcement members are - at ground or other convenient low level and then pretensioned being controllable independently of '. progressively raised to their ?nal positions by continuous and progressive fabrication of their supporting walls,’ columns or other supporting the tensioning pressure of the concrete. X Other objects, advantages and characteristic features of my invention will be apparent from structures. . ' 65 the ‘following description of the several. preferred embodiments illustrated in the provided with packing glands Ii through which vaohtimhallying . ‘ reinforcing wires i2 and, i3 are passed into the drawings, in which mouldwhere the inner ends of said wires are Fig. 1 is a longitudinal sectional 'view of one . fastened to a movable starting head H by suit able wire clamps l5. Thewires l2 are passed ' inwardly through the packing glands II from . form of apparatus which may be used in fabri eating concrete elements or structures by a con tinuous process embodying the principles or my _ invention. - suitable supply reels 16 which may be arranged - in any suitable manner. .In the present instance ' Fig. 2 is a transverse sectional view taken sub-I ‘, stantially along the line 2-2 of Fig.- 1.‘ _ the _'reels i6 are-"shown .carried by supporting Fig. 3 is anenlarged fragmentary transverse‘ '10 strutsnl'l. extending from one end of mould l. ‘The reels l6 are preferably tension. regulating sectional view‘ot the mould?shown in Fig. 1. 9‘ reels from which the wires l2 are paid out only . ' ‘Fig. 4 is an enlarged longitudinal sectional view of the starting head employed iniconjunction . qafter these wires have been stretched and ten .with'the mould shown in the preceding figures. :i' ;_sioned-to‘a predetermined degree by the pulling , and stretching action to which the wires are sub- _ . jected as1 hereinafter described. This ensures ' Fig. 5‘ is a view similar to Fig. 1, but showingv 15 themould means for controlling equipped with the movement pulling and'retarding oi'the 8350;! _ that the wires, i2 will be embedded in the concrete in a 'pretensi‘oned’ condition during passage of ciated starting head. the concrete through the mould. The wires l3 are passed to the starting head I4 from free-running the ,mould equipped with retarding means for 2.0 reels (not shQWIJ) or item some other paying I retarding_therate of movement of the starting Fig. 6 is a view similar to Fig. 1, but’sl’iowingi " ~ out meansqwhich does not impose any appreciable tension thereon. The ‘wires iii are thus embedded head and the concreteas' these‘element's-emergev from the discharge end of the mould. in the concrete passing through the mould to Fig. '7, isa'view illustrating one application or‘ . my invention whereby a mould; such as'shown in 25 serve as a passive reinforcement as‘ ‘distinguished - from the Dretensioned Fig.1, maybeutiiized for iab'ricating- a concrete thewiresl2., element’ or structure'insitu upon a previously be employed‘ vas ' part of r the construction appa ratus. , ‘ ' ' > > a‘ - out maybejequipped with any conventional fric 30 tional, hydraulic, or other restraining device to ~resist;,turni_ngl. movement of the reels until the ' wiresrilhave been stretched and tensioned to a Fig. 7a is a transverse sectional view ‘taken sub! predeterminedvdegree. stantially‘along thelineld-la'ot Fig. . ‘The reelsJG from, which the wires I2 are paid fabricated concrete structure'in‘ such manner as r to fenable'the previouslyYfabricated structure to reinforcement a?orded by “y ‘ ' 1 . ’ ' . V ; ‘ - The-startingheadjll is initially positioned close illustrating a further application of my invention 35 to-theinnerend of dome 9 and is ‘guided, during Figs. _8.' 9 and‘ 10 are'vertical'sectional views part of’ its-travel. bythe surrounding ‘staves 6. whereby parts‘ofa structure may be fabricated ' The end of the starting head-‘nearest the dome " at ground or other convenientlow level and then ‘is covered by a compressible gasket 19 and a metal raised .to their final‘ position by'prog'ressive fab plate 20 securedin place by screws or nails 2|. rication" of their supporting walls." ‘columns; or The,:plate,20 is free to move against the gasket v40 other supporting structures. a " ' Y -' v a viiito compress the latter against- the adjacent ' Fig,#_11 is] a sectional-view of a1;modi?ed type endoi'the starting head.‘ The gasket I9 is made of rubber'or, other resiliently compressible mate 'rial'which is- capableroi substantial lateral ex water vfrom'the interior a's'well as from the ‘outer 45 pansion when subjected to compression between ofjdomejwhich?may'beused in connection with the apparatus shown" in- Figil to‘ drain surplus the plate 20 and the starting head M. A leather . packing ring 22 is secured to the starting head portions . .Fig'. 12 of’the is a sectional‘view mass. _“' -' taken ~ ‘- .-along . A‘ the ~ line .|2.—=-l2'.0f Fig. 11. ‘ ‘ > ‘ " ' so that'it ‘surrounds, and projects beyond the ‘gasket l9 andthe plate 20. This packing ring is , Figs. 1 to .4 inclusive’illustrate'_one_-'form;of apparatus which may be‘ used in" accordance with my. invention for‘ the ‘manufacture of . strength, reinforced concrete by a continuous fab‘- " ' . . , . . . high?“ ricating. process.~ , In v,this case the‘, mould '4, through which the‘ concrete is pumped‘ under pressure, comprises a cylindrical outer shelll'5 designed to withstand‘ internal pressures which iorce'doutwardly into sealing engagement-[with the inner ?anges 801 the staves 8‘ by the afore said lateral expansionv of .the gasket I9. ,This prevents any. possibility of the mortar in the con crete being squeezed between the starting head and the surrounding staves. The packing ring 22 :is secured to the'starting head by nails or screws may be in excess of,“2‘,000 lbs; per square inch. In mostcases, however,jthe internal pressures ' in. ?-The. starting head 14, gasket I9 and plate 20 provided with suitable holes 24 through which to which ‘the-shell is subjected in service will be _ v-are the wires l2 and I3 are passedto the clamps iii. lower their 1000 lbs.vper_"square' inch. Theshell 7 may be made of any suitable material and-is pro 60 ‘ The fabrication of prestressed, reinforced con-' vided with a lining consisting of metal staves 6 ' crete by use. of the apparatus shown inFigs. 1 arrangedin circular series.‘ The cross sectional shape of‘each' stave 6“ is'simiIar to vthat of an I-beam, the outer ‘?ange 'l-‘b‘eing' somewhat‘fwider manner: Plastic concrete is pumped, under suit ' able pressure (usually not substantially less than than, the inner ?ange v8, to facilitate arrangement or thestaves'in circul'ar'series with corresponding ?anges of adjacent staves butted togetherin edge l0 into dome?jand against [plate 20 of starting head “.1 The pressure of the concrete against to edge relation. " " " " ' ' " ' to 4 inclusive is accomplished in the following 2001lbs. per square inch) through pipe connection the starting head ' H stretches and tensions the . reinforcement wires I2 andresults in the start ing head ‘being forced, toward and through the of thestaves is closed at one endgby ahollo'w dome 9 which is open at'its inner end andiis weld- / open end ‘of the mould at a rate which is con trolled, in part, by the effective pressure of the .edvor otherwise secured to said‘?ange's‘. ‘ ‘The in concrete and, in part, by the setting of the ten terior'of dome 9 is connected, by‘ pipeconnection , The mould space bounded bythe [inner ?anges ill, to the delivery side of a conventional con crete pressure pump (not shown) .' Dome 9 is also - . sion regulating means governing the paying out or the wires i2 from the reels I6. In this par 12,413,911 ' ticular instance’ the pressure of the concrete act- -' crete products, such as bricks, tile, or pipe, the incorporation of reinforcement. members in the concrete during the. fabricating process is op ing against the starting head I4 is utilized to stretch and tension the wires l2 so that the latter ‘ - are embedded in the concrete in a‘ pretensioned , tional. _ condition during passage of theconcrete through the mould 4. At the same time successive lengths r of the untensioned wires I 3 are drawn through. a > the mould by the travelling movement of the , starting head VM and embedded in theconcrete to serve as passive reinforcement. ‘ ' In some instances thev desired concrete strength may be obtained by a_ pressure greater or less than that required to produce the desired tension in the reinforcement members [2. To provide for this‘ contingency auxiliary pulling or retarding 10 means may be provided to control the rate of ‘movement of the starting head independently of ' ' As the leather packing ring 22 of the starting head moves away from the dome 9 the concrete the pressure of the concrete in the mould. A simple form of mechanism capable of being ’ comes in direct contact with the inner ?anges 8 - r of the metal ‘staves and, owing to the pressure I used either as a starting head pulling or retard on the concrete, practically all of the water in ,-15 ‘mg means is illustrated in Fig. 5. This mecha excess of the amount required for hydration is nism comprises a feed screw 30 which is attached expelled from the concrete through the Joints , to the starting head bya plate 3| and is slidable ’ formed by and between said ?anges, it being un through a guide opening provided in a cross-head derstood that thesejoints are of such a nature as 32 carried by supporting members 83 attached to permit vwater to be forced through them under 20 to the mould 4. The feed screw carries nuts 34 a pressure‘ and into'the open-ended drain passages £119.26 38 arranged at opposite sides of the cross 28 separating the web portions of the metal ' ' staves. e 'I'his pressure expulsion of excess water ' . - ' a . When the pressure necessary to develop the ‘ from the concrete through the drainage system of desired strength in the concrete exceeds that re the mould 4v permits the concrete to set rapidly 25 quired to produce the desired tension in the rein~ and to develop exceptional strength in the short , forcement members 12, the nut 34 is positioned time required for it to travel fromthe dome 9 to against the adjacent side of cross-head 32 and the opposite or discharge end of the mould. ' , the nut 35 is backed oil a suitable distance from ' The starting ‘head I4 is needed only at .the' the opposite side of the cross-head. During the commencement of the fabricating process to en 30 fabricating process the nut 34 is rotated in con sure the proper tensioning and feeding of the re- ' tact with the cross-head and in the direction inforcement wires l2 and I3 and the development - ' necessary to permit the feed screw and the start of the requisite back pressure on the concrete initially supplied to the mould. .By the time the concrete reaches the discharge end of the mould 35 it has set sufficiently to become bonded to the: reinforcement members 12 and I3 and therefore,‘v takes over the work of pulling these members ing head to be forced toward the discharge end‘ of the mould'at' retarded rate of speed by the pressure of the concrete acting against the start ing' head. In this case the rate of'travel of the starting head is determined by the speed of‘roé tation of the nut 34. In practice the nut 34 will preferably be operated by worm gearing or other on the concrete travelling through the mould is 40 operating means capable of regulation to turn also developed independently of the ‘starting head» the nut at any speed necessary to produce the soon after the commencement of the fabricating tension desired in the reinforcement members l2. through the mould, .The requisiteback pressure . process. It will be apparent that forward move When the pressure necessary to develop the I desired strength in the concrete is less than that > ment of the concrete is resisted through resisting of forward movement of the reinforcement mem bers which are attached initially and indirectly 45 required to produce the desired tension in the reinforcement member 12, the nut 35 is posi tioned against the crossehead and the'nut 34 is to the forward end of the concrete through the starting head 14 and thereafter become directly attached or bonded to said forward end as the concrete sets, such action'serving the double func backed an appropriate distance from the cross head. The nut 35 is then rotated in contact with the cross-head in‘ the proper direction and at ' tion of compressing the concrete to densify it and > ' su?lcientspeed to cause the feed screw 30 and expell the surplus water and to place the rein . the starting headv 4| to travel toward the die forcement under tension. I charge end‘ of‘ the mould more rapidly than The foregoing method of using the apparatus‘ ‘ would be the case if these parts were being moved shown in Figs. 1 to 4 inclusive enables excep 65 by the pressure of the concrete in’ the tionally high strength prestressed reinforced con crete elements‘or structure of inde?nite length : to be manufactured by a continuous fabrication - form.- - - In Fig. 6 I have‘ shown another form of mech anism which may be used for regulating the process with the aid of a mould of relatively short tensionlng of the wires H by retarding the move length. By regulating the pressure on the con. .60 ment of the starting head and the fabricated crete during its passage through the mould itjis‘ ' concrete as: they emerge from the open or dis ' possible to control the strength developed 'by‘ charge end of the mould. In this case the emerg the concrete in the short time required for it to . ing starting head or concrete, as the case may travel from the dome 9 to the discharge endof .the mould. Insofar as certain features of the in a ‘be, is engaged by pressure applying retarding ‘shoes 31 which aremovably supported by suit vention are concerned, the reinforcement mem able supporting members 38 so as to be capable bers may be omitted entirely or may be embedded of movement in a direction at right ‘angles'to in the concrete in ‘either a passive or a preten the axis of the mould. The shoes 8‘! are pressed sioned condition. In some cases'all the reinforce ment members may be embedded in the concrete .70 against the starting head or the concrete by ‘pressure applying springs 30 , the loading of in a passive condition while, in other cases, all the reinforcement members may be embedded in ' - which may be regulated by operation of suitable adjusting screws 40 which are threaded through‘ the concrete in‘ a pretensioned condition'.. In a supporting ring 4| and are provided, at their certain cases where the main consideration is the ‘, continuous fabrication of high strength con inner ends, with spring seats 4? bearing against 2,418,911 . 7 ~ - ' the outer ends of said ‘springs. The. supporting ring 4i may be supported from the adjacent end member movable between the inner and outer series of staves. In all vother respects, however, thelannular or ring-shaped mould willbe sub stantially the same as the mould shown in Figs. -1 and 7. As a matter of fact, the shape of the vAnother application of the invention is illus mould is not a- critical factor since it will nat trated in Flgl' 7. ‘ In this instance the, extruded .urally be varied according to the shape of the concrete structure is built in place upon a pre concrete element or structure to be produced in viously formed structure which is used as part of e with the principles of my invention. the construction apparatus. The built-in-place' accordance structure is indicated at 45 and lshere shown as 10 Figs. 8, 9 and 10 illustrate a further applica tion of the invention whereby ?oors, beams, roofs a simple column or pole erected ‘on a preformed or other elements of a structure may be fabri ' base structure 45 which may represent either a cated at ground or any other convenient ‘level foundation or a precast base section of the. col andthen raised to their final position by pro- . umn or pole. The structure 45 is built in situ of mould 4 by suitable supporting arms 43 or. ' inany other‘ desired manner. ' by pumping concrete upwardly through a cavity 15 gressive fabrication of their supporting walls, _ 41 of the base structure 45 and through a rela tively short vertically disposed mould 4 which, except for the omission of the Home 9, is exactly columns or other supporting structure. In describing the illustrated example of this last mentioned application it will be assumed that the structure to be fabricated is a circular the same as the mould 4 described in connections with Figs. 1 to 4 inclusive. In this case the 20 concrete tank. The foundation 80 is ?rst fabri~ cated as a precast structure'provided with an mould 4_is tied to the base structure 46 by anchor annular mold forming cavity 6| extending down bolts 48 having their lower ends embedded in wardly from the upper surface thereof and with said structure,'said bolts extending upwardly be any suitable number of curved passages 52 ex tween the staves 5 of the mould‘ 4 and being equipped at their upper ends with stave-engag 25 tending from the bottom of the cavity to the outer side of the foundation, each passage 62 ing washers 45 and clamping nuts 55. The concrete is-pumped into cavity 41 through a pipe 52 having an upwardly curved inner end 53 open ing into the bottom'of said cavity. The outer end of pipe 52 is provided with a. T-connection 30 54 having one branch connected, by pipe con-_ nection 55, to the delivery side of a concrete pressure pump (not shown). . Another branch being connected, by suitable pipe connections 63, to the discharge side of a concrete pressure pump (not shown) or to a header to which concrete is pumped under pressure by said pump. Each annular wall of mould cavity 6| is pro vided with a drainage lining consisting of a cir— cular series of staves 65 corresponding to the ' previously mentioned staves 8. The staves 65 58 of ,T-eonnection 54 is ?tted with a packing gland‘ 51 through which is passed a reinforcing 35 of each series are held in place by anchor bolts 66 and by packing sand 61, the latter being inter wire l2 which is fastened tothe starting head HpoSed between the outer ?anges of the staves and 7- H by a clamp IS in the same manner as de the adjacent side wall of the mould cavity. The scribed in connection with the reinforcement anchor bolts 65 correspond to the previously men wires i2 shownin Fig. 1. e As the starting head l4 (Fig. '7) is forced up 40 tioned anchor bolts 48 and have their lower por paid out from a tension regulating reel such as that indicated at IS in Fig. l. The starting head and the concrete beneath it will continue to travel tions embedded in-the foundation 60. The inner ?anges of each'series of staves 65 are initially covered by thin liner plates 68 which are dis placeable as hereinafter described. A vertically pressure through the pipe connection 52 so that suitable durable material, is initially arranged , wardly it serves to tension the wire l2 which is ' upwardly as long as concrete is pumped under 45 displaceable pallet 10, made of metal or any other a pole or column of any desired height, within‘ practical limits, may be erected in situ .upon the ' at the bottom of the mould cavity Bl so that it covers the upper ends of the passages 62. This pallet is provided with openings through which foundation structure 46, and will be tied to such structure by the concrete ?lling left in the cavity 50 tensionable reinforcement members, here shown ’ 41 and also by the pretensioned reinforcement as steel .wires ‘II, are passed upwardly into the mold cavity Bl. The wires ‘Il may be led to the member I! which, ‘in the completed structure, is bonded to both the built-'in-place structure 45 and the preformed base structure 46. mould cavity 6! through the pipe connections 63 cavity v4‘! through any desired arrangement of ing glands ‘l2. and passages 62 or in any other suitable manner, I have shown only a single wire l2 attached to 55 said wires being paid out from tension regulat ing reels such as those described in connection the starting head l4 in Fig. ‘I but it’Will be un with Fig. l or from any other tension controlling derstood that any number of such wires may be means. The opening in theepipe connections 63 passed into the. cavity 41 and attached to the through which the'wires ‘II are passed to the starting head to give any desired amount of re inforcement. Such wires may be led into the 60 mould cavity 6| are provided with suitable pack passages provided for this purposes so that they, may be located in the completed structure in any desired manner.- ‘ ' In the use of the construction apparatus shown in Figs. 8, 9 and 10, concrete is first poured into the mould spaces bounded by the inner and outer In those cases in which it is desired to. pro 65 liner plates 68 to form an annular wall section 14 resting on the pallet 10, said wall section duce a ring-shaped or annular concrete struc being bonded to the portions of the reinforcement ture such as an annular wall or pipe it is obvious that the mould] shown in Figs. 1 and 7 maybe 4‘ wires 1| extending above said pallet. A concrete ' roof member 15 is then fabricated in place on replaced by moulds of annular form; that is to. say, moulds comprising‘ spaced inner and outer 70 top of the wall section 14. After these parts of the tank structure have been completed plastic ' vannular walls having their inner surfaces lined concrete is pumped under pressure through the "by metal staves such as the‘previously described pipe connections 63 and passages 82 and against metal staves 6. When annular moulds of this type are used it is necessary, of course, that'the - ‘the pallet ‘III. As this concrete rises in the mould starting head be also constructed as an annular 75 space bounded by the liner plates 68 it causes the r 9 2,418,911 10 pallet 10 and the wall section 14 to be progres sively raised, as indicated in Figs. 9 and 10, to any desired height. The liner plates 68 move up wardly with the wall section 74 and the pallet 10 until they are raised clear of the mould and when the principles 01' my invention are ap plied to the continuous fabrication of concrete elements or structures of great mass it is possible that the time required for expelling excess water from the concrete through the drainage openings are free to drop away or to be removed from the wall section 14. This progressive fabrication of ' the remaining portion of the tank wall by pump ing concrete upwardly through the mould con provided by the staves lining the inside of the mould will be so great that the rate of manufac- ' ture may be seriously retarded. This can be readily explained since the high pressure on large tinues until a wall of the desired height is ob masses of concrete creates so much friction on the tained. The pressure on the pumped concrete staves that if the moulds are made long enough and the drainage of water therefrom during pas to provide adequate drainage time, the friction on sage of such concrete through the mould may be ‘ > the staves may be so high as to make it impos so regulated in relation to the length of the mould sible to maintain the required‘movement of the as to ensure that the pumped concrete will set 15 concrete through the mould. This di?iculty, and acquire the requisite strength by the time it however, may be overcome in various ways by reaches and commences to emerge from the top providing‘suitable means for draining excess wa of the mould. ' ter from the interior of the concrete mass. For In connection with Figs. 8 to 10 inclusive, it example, in the case of an apparatus such as will be understood that a floor, horizontal beams 20 shown in Fig. 1, the dome 9 may be provided or girders, or any other'type of superstructure, with suitable bleeders ‘I1 (Figs. 11 and 12) may be superimposed on and Joined to the 'wall through which excess water is drained from the section 14 before the latter is raised by the pres interior portion of the mass of concrete supplied sure of the concrete which is pumped to the to the mould. As here shown each of these mould through the passages 62' provided, of 25 bleeders consists of four segments 18 ?tted to-, gether to form, in effect, a. cylindrical bar, the course, that the weight of the superstructure is inner corners of the segments being champered within the lifting capacity of the apparatus as off to provide a central drain bore 19. Inv this measured by the pressure of the pumped con case excess water is forced from the concrete crete on the pallet 10 less the friction of the mould and the tension in the pretensioned re inforcement members ‘II. It will also be understood that ‘the principles of construction exemplified by the showing in 30 mass into the drain bores of the bleeders through the inner ends of‘ said bores and through the joints formed by and‘ between the segments 18 which are suitably fastened to the dome 9., If ‘ it is desired to pass the reinforcing wires 12 and Figs. 8 to 10 inclusive may be applied in a variety of ways dependent upon the type of concrete 35 I3 into the mould through the bleeders. this may be accomplished as shown in Fig. 11, it being ‘ structure to be erected in accordance therewith.‘ noted that the wires are passed through packing It is possible, for example, to provide a series of moulds in which the upper sections of support ing members, such as posts or columns, are ?rst glands 80 located at the inner ends of the bleeders. In this case most of the water drain ing into the bores 19 of the bleeders is forced precast and then raised to their ?nal position by through the joints formed by and between the forcing concrete upwardly through the mould ‘to segments 18 of each bleeder. If it is desired to progressively form the remaining portions of the have the bleeders open at both ends the wires length of said columns, posts, or other supporting may be carried through the dome 9 by means of members. Obviously, the number, shape and de tails of the moulds used for fabricating different 45 separate packing glands as shown in‘Fig. 1. Having thus described my invention, what I types of concrete structures in accordance with claim is: the principles'of my invention will vary accord— 1. The fabrication of vertical concrete ele ing to the design of the structure to be erected ments or structures of considerable height by a and other conditions which must be taken into 50 continuous process comprising extruding concrete consideration. upwardly through a short vertical mould asso When fabricating vertical structures such as ciated with a preformed concrete structure to those illustrated in Figs. 7 and 8 it is feasible and, thereby fabricate an extruded concrete element in some cases, may be necessary or desirable to extending a substantial distance above said mould progressively increase the pressure on the con and having its base portion bonded to and sup crete in the mould as the structure rises vertically. 55 ported by said preformed supporting structure. Thus, the pressure to which the concrete is sub 2. Apparatus for use in making high strength jected in forming the ?rst section of 'the struc concrete elements or structures by a continuous ture .in the mould may be progressively increased fabricating process comprising a, mould, means so that each succeeding section will have greater for forcing concrete under pressure through said density and strength than the preceding section. 60 mould, a travelling starting head initially ar In this connection it will be understood that the ranged in said mould in the path of movement of progressive increase of pressure here referred to the concrete from its point of entry to its point may be greater than that which is necessary to of discharge from said mould, said starting head carry the increasing load due to the increasing comprising a body portion, a movable pressure height and. weight of the structure which is being 55 plate carried by said body portion and against fabricatedand raised. In this way it is possible‘ which the concrete‘is extruded, a gasket inter to increase the strength of the concrete in suc posed between said body portion and said plate ceed’ng sections of the structure which is formed and made of resiliently compressible material ca in the mold without increasing‘ the size and pable of substantial lateral expansion when sub thickness of the sections. In other words, the 70 jected to compression between said plate and said density and strength of the concrete may be pro body portion, said plate being movably connected gressively increased from the top to the bottom to the body portion so that it is moved toward of the structure so that the strength of each and relatively to the body portion by the pressure section may be made suflicient to carry the cal of the concrete extruded thereagainst and thus culated load imposed thereon. 75 serves to effect compression and lateral expansion L 11 ~ ' 2,413,911 , " - a travelling starting head adapted to be initially of said gasket and a packing ring carried by said ' arranged in said mould in the path of movement of the concrete from its point of entry to its point ‘of discharge from said mould, the apparatus being adapted to have reinforcing elements ex body portion and encircling said plate and gasket, said packing ring being adapted to be forced out wardly into ‘sealing engagement with the sur rounding wall structure of the mould by the lat eral extension of said gasket and reinforcing ele ' tending into said mould and anchored to the starting head so that successive lengths of the re inforcing elements are drawn by said starting to the body portion of said starting head so that , head toward and through the concrete discharge successive lengths of the reinforcing elements ' are drawn into and through said mould by-move 10 opening of the mould, tensioning means from ments extending into said mould and anchored which the reinforcing elements are passed to said ment of said starting head toward and'through the concrete discharge opening ‘of the ‘mould, ‘said reinforcing members being thereby em starting head, and means for determining and controlling the rate of travel of the starting head independently of the pressure of the concrete which is extruded against the starting head. beddedin said concrete as it passes through the mould. I ' ' , ' , 8. Apparatus for use in making high strength ' ‘I concrete elements or, structures by a continuous 8. The method of fabricating a concrete pole or column which comprises forming the base sec tion ‘of the pole or column with an internal ’ fabricating process, comprising a mould through which concrete can be forced under pressure, a through passage extending downwardly from the top of said section and then completing said pole 20 travelling starting head adapted to be initially ar ranged in said mould in the path of movement of or_ column by extruding concrete upwardly the concrete from its point of entry to its point of through said passage. , discharge from said mould and‘adapted to co 4. The method of fabricating concrete build operate with reinforcing elements extending into ing structures or elements which comprises ini tially fabricating a precast concrete section with 25 said mould and anchored to the starting head so that successive lengths of the reinforcing ele ments are drawn into and through said mould by a through passage, arranging a relatively short mould against a surface of said section so that one end of said passage opens into said mould, movement of said starting head toward and throughthe concrete discharge opening of the extruding concrete through said passage and said mould to thereby fabricate a further extruded 30 mould, tensioning means from which the rein- . forcing elements are passed to said starting head, section of the concrete structure or element in and means engageable with the starting head to situ against the initially fabricated precast sec retard the travelling movement thereof toward tion, and draining water from the extruded con the discharge end of the mould. crete during its passage through the mould so 9; Apparatus for use in making high strength that the extruded concrete is transformed from a concrete elements or structures by a continuous plastic to a high strength granular mass by the fabricating process, comprising a mould through 3time it reaches and commences to emerge from the mould. which concrete can be forced under pressure, a - travelling starting head adapted to be initially ar 5. The method of fabricating concrete build ing structures which comprises initially fabricat 40 ranged in said mould in the path of movement of the concrete from its point of entry to its point of discharge from said mould and adapted to coop erate with reinforcing elements extending 'into face thereof and with internal passages extending said mould and anchored to the starting head so from the bottom of the mould cavity. to an ex ternal surface of the foundation, arranging a 45 that successive lengths of the reinforcing ele ments are drawn into and through said mould by movable pallet on the-bottom wall of the cavity movement of said starting head toward and so that it covers the ends of the passages opening ' through thev concrete discharge opening of the into said cavity, introducing concrete into said - ing a precast concrete foundation'with a mould cavity extending downwardly from the upper sur- ‘ mould, tensioning means from which the rein- ' forcing elements are passed to said starting head, 60 by form a. moulded concrete section adapted to cavity through the top opening thereof to there and means operable to increase the speed of travel of the starting head toward the discharge occupy an elevated position in the finished struc ture, arranging movable liner plates in said cav ity prior to the aforesaid introduction of concrete '_therein to thereby prevent bonding of the in troduced concrete to the defining walls of the cav ity and then extruding concrete through said passages and cavity to raise said concrete section to its ?nal position and to simultaneously form end of the mould. _ 10. Apparatus for use in making high strength 55 concrete elements or structures by a continuous , extrusion type fabricating process, comprising an extrusion mould through which concrete can be _ extruded under pressure, through said mould,- said mould being provided with a drainage lining 6. The method set forth in claim 5 which in 60 through which excess water is drained from por tions of the concrete adjacent said lining, and 'cludes the step of passing the leading ends of long means extending into the interior of the mold lengths of reinforcing members into said mould an extruded supporting structure for said section. ' ' and having a passage therethrough for draining cavity prior to the initial ?lling of the cavity to water from the interior of the concrete mass dur form said concrete section whereby said leading, ' end portions of the reinforcing members are 65 ing its passage through said mould. bonded to said section so that, during subsequent » raising of said section to its ?nal position, succes sive lengths of the reinforcing members‘ are drawn into said cavity and are bonded to the ex truded concrete during its passage through said 70 cavity. ' . , 7. Apparatus for use in making high strength concrete elements or structures by a continuous 11. A method of fabricating high strength con crete structures, which consists in extruding con crete under pressure through a mold, and simul taneously therewith placing the moving concrete in the mold under predetermined increased pres sure forcing surplus water therefrom by resisting at its forward portion normal passage of the con crete through the mold, thereby facilitating the setting of the concrete and increasing its strength. fabricating process, comprising a mould through 12. A method of fabricating high strength con which concrete can be extruded under pressure, 76 13 2,418,911 crete structures, which consists in extruding con c'rete under pressure through a mold, and simul- . ' taneously therewith placing the concrete in the , mold under predetermined increased pressure forcing surplus water therefrom by resisting for 14 mold, simultaneously therewith tensioning said reinforcement and increasing the extruding pres sure on the concrete by restraining movement of the reinforcement at a point rearwardly of the mold and utilizing the extruding action of the concrete to draw the‘ reinforcement through the ‘ through the action of resisting forward movement " mold against such restraint, modifying the ex -of reinforcement attached to said forward end truding pressure required and the resultant den ‘ of the concrete and extending rearwardly there sity and strength of the extruded concrete by ap from through the mold and said mixture, thereby 10' plying external force to said forward end of the facilitating the setting of the concrete‘ and in concrete in a direction longitudinally of the mold, creasing its strength. and bonding the concrete to the tensioned rein 13. .A method of fabricating high strength rein- ' ‘ forcement as they exit from .the mold, thereby forced concrete structures, which consists in ex facilitating the setting of the concrete and plac truding concrete under pressure through a. mold, 15 ing the extruded concrete under permanent com ward movement of the concrete at its forward end simultaneously therewith placing the moving pression. . concrete in the mold under predetermined in 16. The method defined in claim 15 in which creased pressure forcing surplus‘ water therefrom said external force is applied in a direction op by resisting at its forward portion normal pas posing forward movement of the concrete, there sage of the concrete through the mold, passing 20 by increasingthe density and strength of the ex steel reinforcement under tension through the truded concrete. . mold simultaneously with the concrete, and bond 17. A method of fabricating a high strength ing the tensioned reinforcement to the concrete concrete structure in situ on. and against a pre as they emerge from the mold, thereby facilitat formed concrete structure, which consists in pre ing the setting of the concrete and placing the 25 forming a concrete structure with a cavity therein extruded concrete under permanent compression. open to' the side thereof on ' which the high 1 14. A method of fabricating high strength re~ strength structure is to be fabricated, associating inforced concrete structures, which consists in an extruding mold with the preformed structure extruding wet plastic concrete together with steel at said cavity, and forcing concrete under pres reinforcement under pressure through- a mold, 30 sure into the cavity and outwardly through the said reinforcement being attached to the forward mold. end of the concrete as it emerges from the mold 18. The-manufacture of concrete elements or _ and extending rearwardly therefrom through the structures by a continuous process, comprising mold, simultaneously therewith tensioning said continuously extruding the concrete through a reinforcement and increasing the extruding pres 35 mold under pressure forcing excess water from sure on the concrete by placing a, predetermined and densifying the concrete, and gradually vary . restraint on the movement of the reinforcement ing said pressure during passage of the concrete at a point rearwardly of the mold and utilizing through the mold to thereby modify the density the extruding action of the concrete simultane and strength of successively extruded portions ously to tension and draw the reinforcement 40 of the concrete. through the mold against such restraint, whereby 19. The manufacture of concrete elements or forcing excess water from the concrete and out structures by a continuous process, comprising wardly of the mold, and bonding the concrete continuously extruding concrete together with re to the tensioned reinforcement as they exit from inforcement through a mold under pressure forc the mold, thereby facilitating the setting of the 45 ing excess water from and densifying the con concrete and placing the extruded concrete under crete, applying said pressure to a tensioning of permanent compression. the reinforcement as it passes through the mold, ' 15. A method of fabricating high strength re gradually varying said pressure during passage of inforced concrete structures, which consists in the concrete through the mold to thereby modify extruding concrete together with steel reinforce 60 the density and strength of successively extruded ment under pressure through a mold, said rein portions of the concrete, and bonding the ten forcement being attached to the forward end of sioned reinforcement to the concrete as they the concrete as it emerges from the mold and emerge from the mold. extending rearwardly therefrom through the CURZON DOBELL. > Certi?cate of- Correction 1 Patent No. 2,413,911. . 4 _ . Y ‘ January 7, ,1947. OURZON’ DOBELL It is hereby certi?ed that errors appear in the printed speci?cation of the above numbered patent requiring correction as follows: Column 7, line 62, for the word = “purposes” read pur ose; column 12, line 58, claim 10, strike out the words and comma. “through said moul ,”; and that ‘the said Letters ‘Patent should be read with thcse ' ggirections therein that the same may conform to the record of the casein the Patent . 0e. .e - Signed'and sealed this 25th day of March, A. D. 1947. LESLIE FRAZER, First Assistant Commissioner of Patents.