US3049786A

US3049786A - Apparatus for making prestressed structural members

Info

Publication number: US3049786A
Application number: US738564A
Authority: US
Inventors: Cordis W Jones
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-05-28
Filing date: 1958-05-28
Publication date: 1962-08-21
Anticipated expiration: 1979-08-21

Description

c. w. JONES 3,049,786

APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Aug. 21, 1962 3 Sheets-Sheet 1 Filed May 28, 1958 IIIIIIIIL INVENTOR CORDIS W. JONES TORNEY Aug. 21, 1962 c. w. JONES 3,049,736

APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Filed May 28, 1958 3 Sheets-Sheet 2 GROUND LEVEL FIG. 3

INVENTOR. CORDIS W. JONES ZMMMM ATTORNEY Aug. 21, 1962 c. w. JONES 3,049,736

APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Filed May 28, 1958 5 Sheets-Sheet 3 INVENTOR. CORDIS W. JONES ATTORN EY 3,049,786 APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Cordis W. Jones, Wichita, Kans. (5142 W. Nevada Place, Denver 19, Colo.) Filed May 28, 1958, Ser. No. 738,564 4 Claims. (Cl. 118) This invention relates to concrete. In a more specific aspect, this invention relates to concrete members or articles of manufacture. In a still more specific aspect, this invention relates to such members or articles of manufacture and method and means for producing them.

In yet a more specific aspect, this invention relates to means for making so-called pre-stressed concrete members or articles of manufacture having therein tensioned reinforcing members of wire and/ or cable. Another specific aspect of this invention relates to a new method to produce such pre-stressed concrete members. In still a more specific aspect, this invention relates to means for making structural members of concrete known as pre-stressed concrete beams, etc., having therein reinforcing members preferably of Wire and/or cable which are under tension and which are pre-tensioned before manufacture of such concrete structural members, and this invention specifically relates to a method of making such pre-stressed concrete members, such method and means preferably specifically pertaining to means and methods of making such as pre-stressed concrete I-beams, channel beams, double T beams, poles, piling, beams of square cross section, beams of fluted-shape in cross section, and the like.

Concrete has long been known, and it is used for the construction of many different things, for example, highways, footings and foundations for buildings, building walls and ceilings, roofs, and the like, where the concrete is in monolithic form, and normally in these uses reinforcing members of metal rod are built into the slabs or sections of monolithic concrete to strengthen same. These reinforcing metal rods are merely positioned to extend through the forms for making the concrete section and are not placed under tension before contacting with the concrete.

Fairly recently relative to time, it has been known and is common in the prior art to make and use so-called prestressed concrete members, and these can be and are used for all kinds of structural purposes, generally being usable where wood or metal beams, poles, pilings, etc., can be employed in the building and construction industries. These pre-stressed concrete structural members of beam, pole, piling, and the like, shape are built and formed with substantially longitudinal reinforcing metal wire and/or cables therein embedded in the concrete. These reinforcing wires and/or cables pass through the mold means employed to form the concrete member of desired shape prior to introduction and contact therewith with the concrete to form the member, and the reinforcing wires and/ or cables are placed under tension, with such tension being maintained on the wires and/or cables during the setting and for a portion of the curing time of the member being formed. The result is a concrete beam member which is pre-stressed prior to use in construction, and these beams are much stronger than the beam which has no pre-stressing. The advantage of this to the construction or building industry is apparent. Smaller members can be employed to carry the same load as a much larger beam which is not pre-stressed. Less material can be used in construction of the beam members, and materials of relatively low cost. Economic concrete can be used in many places to replace relatively expensive steel and wood. Concrete can be used to construct the frame work of buildings, without the necessity 3,049,786 Patented Aug. 21, 1962 of forming up and pouring on the job. And, the concrete structural members will outlast almost any other kind of suitable replacement material, not being subject to corrosion from the elements, and not being attacked by such as termites.

In the prior art it has been a practice to make these so-called pro-stressed concrete beams or poles by simply building a stationary form of wood or metal, stretching reinforcing wires and/ or cables through the mold in proper position, tensioning the reinforcing wires and/ or cables to the desired tension, pouring concrete into the mold to fill it, letting the concrete set up in the mold, removing the mold from around the formed concrete beam or vise versa, allowing the formed concrete beam to cure to the desired point, and cutting of the reinforcing wires and/ or cables at the ends of the beam. This method and means of producing the pre-stressed concrete beams is very tedious, expensive, and time consuming. Setting and curing times of up to 96 hours are commonly employed, and this ties up a lot of form equipment. Also, it is very diflicult in operation to handle the forms, for example, to space them properly to make it easy and rapid to introduce concrete thereinto.

Other method and means have been proposed, one of which is to move individual forms in series along a base, bringing them to a halt to fill the forms and then moving the forms to an agitation and curing area, and in this means the reinforcing wires and/ or cables are common to all the forms in the series being fed from a plurality of spools of the rein-forcing material. These means perhaps make it easier to introduce the concrete into the forms, since they are moved to the dispensing means, but the tieing up of the equipment and expensive time consumption makes the proposed method and means disadvantageous. Further, difiiculty is encountered in properly feeding out the reinforcing wires and/ or cables because of the necessity of maintaining considerable tension thereon. All of the methods and means of the prior art are undesirable in several respects.

I have invented new apparatus for making concrete members. The apparatus has a base. A mold is used which has a passageway therethrough. In operation the concrete is introduced into the mold through means therein or therewith providing for such. The mold is mountable to move relative to the base, and means are preferably provided to move the mold in relation to the base. The new apparatus of my invention is adapted to make a concrete member by moving the mold relative to the base and introducing concrete into the mold. Preferably, a mold member is employed which moves along the base, with the base forming a portion of the mold, usually the bottom of the mold, and reinforcing members, preferably metal wires and/ or cables, pass through the passageway in the mold under tension. The mold member in operation moves relative to the reinforcing members. By the new method of my invention for making concrete members, concrete is passed into a mold movably mounted to move relative to a base. A portion of the concrete is solidified in the mold during operation. And, during operation the mold is moved relative to the base to a position out of contact with a portion of the resulting concrete solidified in the mold to thereby produce a portion of a formed concrete member. Preferably, reinforcing members are provided and pass through the mold and are maintained therein during the introduction and contact with the concrete. These, of course, are preferably metal wire and/or cable reinforcing members.

The new method and means of my invention for making concrete members is very advantageous. It can be used in a continuous operation to make a plurality of such concrete members using one mold means. Equipment and apparatus is not tied up in time consuming and expensive delay. The apparatus can be made very functional to be easily transportable. In making pre-stressed concrete beams, poles, piling, and the like, the reinforcing metal wires and/ or cables are pre-tensioned and mounted, and remain stationary during'the forming, setting, and curing stages of the process. Thus, the apparatus is very reliable in use. The mold means employed in the apparatus is very accessible in operation so that the concrete can easily and conveniently be introduced into the mold. Moving equip ment hauling ready-mixed concrete which is available in almost every city of any size can be brought up in close relation to the mold during operation to pass or dump the ready-mixed concrete into the mold of the apparatus. This can be done continuously or semi-continuously in forming a pro-stressed concrete beam or a plurality of beams. The new apparatus of my invention can be made any length desirable, and it can be made to produce in one continuous operation a great number of concrete members, using a plurality of individual mold means or members which operate in parallel, each of the units in parallel producing a series of concrete members, if desired. The new apparatus of my invention is easy and inexpensive to manufacture, and reliable and economic in use and to repair.

Itis an object of this invention to provide new concrete handling method and means.

It is another object of this invention to provide new method and means for making concrete members or articles of manufacture.

Still another object of this invention is to provide new method and means for making so-called pro-stressed concrete members or articles of manufacture having reinforcing members in tension therein, preferably wire and/ or cable reinforcing members.

Yet another object of this invention is to provide new method and means for making such pre-stressed concrete structural beams continuously or semi-continuously, and such *beams having reinforcing members preferably of metal and/ or cable therein which are pre-tensioned before manufacture of such concrete structural beams.

It is still another object of this invention to provide new method and means for making pre-stressed concrete structural beams, poles, piling, and the like, which is easy and inexpensive to make and use, and reliable and economic in use.

Other objects and advantages of the new method and means for making concrete members of my invention, particularly pre-stressed concrete structural members having pre-tens'ioned metal wire and/ or cable reinforcing members therein, will become apparent to those skilled in the art upon reading this disclosure.

Drawings accompany and are a part of this disclosure. These drawings depict preferred specific embodiments of the new apparatus of my invention for making pre-stressed concrete structural members, and it is to be understood that the drawings are not to unduly limit. the scope of my invention.

In the drawings,

FIG. 1 is a perspective view of a preferred specific em.- bodiment of the apparatus of my invention designed to make continuously or semi-continuously a pre-stressed concrete structural beam of substantially I-beam shape, or a plurality of such pre-str-essed concrete beams.

FIG. 2 is an enlarged partial cross-sectional view taken on line 22 of FIG. 1.

FIG. 3 is a view taken on line 3-3 of FIG. 2.

FIG. 4 is a view taken on line 44 of FIG. 2.

FIG. 5 is a side elevation view, cut away in the central portion, of a pre-stressed concrete structural I-beam made with the apparatus of FIGS. 1 through 4 of my invention, and by the new method of my invention.

FIG. 6 is a perspective view of a preferred specific embodiment of reinforcing member deflecting means of my invention which is preferably removably mountable in 4 cooperative combination with the apparatus of my invention shown in FIGS. 1, 2, and 4.

FIG. 7 is an enlarged transverse cross-sectional view through the mold member of the apparatus of my invention shown in FIGS. 1 through 4, and showing in crosssection a formed and reinforced pre-stressed concrete structural I-beam.

FIG. 8 is a side elevation view of a preferred specific embodiment of bulkhead means of my invention preferably used with the apparatus of my invention to provide for producing pie-stressed concrete structural beams wherein the reinforcing members are not parallel to the longitudinal axes of the beam produced, but only sub stantially longitudinal thereof.

FIG. 9 is a perspective view partially cut away of a pre ferred specific embodiment of apparatus of my invention wherein the mold means depicted is such as to produce concrete members in parallel operation, and on a base and other means similar to that depicted in FIGS. 1 through 4.

Following is a discussion and description of my invention made with reference to the drawings whereon the same reference numerals are used to indicate the same parts and/or structure. The discussion and description are made in connection with preferred specific embodiments of the new apparatus and methods of my invention for making concrete members, and it is to be understood that the discussion and description are not to unduly limit the scope of my invention.

Referring now to the drawings, FIGS. 1 through 7, a preferred specific embodiment of the apparatus of my invention is shown for making an I-beam of pre-st-ressed concrete, such beam having pre-tensioned metal wire and/or cable reinforcing members approximately longitudinal the longitudinal axis of the I-beam and embedded therein. The apparatus has a base 11 which is preferably elongated to make one or more beams, and the base is relatively smooth and flat in its operating portion which is central of the sides of the base. End members 13 are at opposite ends of base 11, and they are positioned in mirror image relation as shown in FIG. 1 of the drawings. The base 11 and end members 13 can be made of any suitable material, such as concrete, metal, and/or wood, and the base 11 can be made integral with end members 13, as indicated in the drawings, or the end members 13 can be separate from the base and anchored or set into the ground. Also, if desired, base 11 can be made in sections to make the apparatus more portable. I have found it convenient for a stationary location to make base 11 of monolithic concrete reinforced with metal rod, with the base extending down into and set into the ground (FIG. 2). The outer foundation sections 15, and an inner foundation section 17 have been found suitable and desirable for such an installation. The end members 13 can suitably be poured and formed at the ends of base 11 with the lower portions of end members 13 extending down into the ground, if desired.

The base 11 has guide means rigidly secured thereon and formed by spaced and parallel members 19 which are preferably metal angle irons suitably 'bolted to the base, such as 'by setting bolts into the concrete of base 11. Of course, other suitably shaped members can be used to provide these guide means, and if the base is made in sections the guide means can be mounted on each section to coincide to provide a continuous guide when the sections are placed and positioned end to end for use.

In operation and prior to the use of the new apparatus of my invention to produce pre-stressed concrete beams, a plurality of metal wire and/or cable reinforcing members, preferably of steel, are stretched between the end members 13 longitudinal of base 11 and in spaced relation thereto. These reinforcing metal wire and/or cable members 21 can be used in any number and position desired. They are pre-tensioned and maintained under tension during the forming of the concrete beam member, the solidifying step, and during at least a portion of the curing operation to finally produce the pre-stressed concrete beams. End members 13 are provided with attachment means 23 for mounting and holding wires and/or cables 21 in tensioned condition during the beam forming operation. Any suitable means can be used to stretch reinforcing members 21 and put them under desired tension. The wires and/or cables common to the prior art for producing pre-tensioned and pre-stressed concrete beams can be used with the apparatus of my invention to produce such pre-stressed concrete beams by the new method of my invention.

A plurality of wire and/ or cable reinforcing member deflecting assemblies 25 are removably mounted on base 11 in spaced relation, and in operation wires and/or cables 21 contact these assemblies 25, with the wires and/ or cables deflected out of true parallel alignment with base 11. Also, deflecting assemblies 25 can be employed to pre-tension wires and/or cables 21 by deflecting them from out of true or substantially true straight alignment when they are stretched between end members 13 and secured thereto by mounting means 23. The manner of doing this will be set forth hereinafter. Deflecting assemblies 25 preferably have a plurality of substantially vertically positionable members, namely middle member 27 and side members 29. Preferably these

members

27 and 29 are constructed of steel rod or pipe. A plurality of spaced and horizontally positionable members are preferably rigidly mounted on

members

27 and 29 in any suitable manner to produce a Christmas tree-type of arrangement, namely lower horizontal channel member 31 mounted on

members

27 and 29 and middle and upper channel members 33 mounted on member 27. It has been found suitable to

weld members

31 and 33 to

vertical support members

27 and 29, and in producing a prestressed concrete beam by the new method and means of my invention, these members remain in the beam embedded therein upon producing same. This is accomplished after forming the beam by cutting off the lower end portions of

members

27 and 29 along the bottom of the beam as formed.

The deflecting assemblies 25 are preferably made removably mountable on base 11. Heavy anchoring bars 35, preferably of steel, are mounted in transverse recesses 37 formed in the top of base 11. Two bars 35 are mounted in spaced relation in each recess 37 as shown in the drawings. Bars 35 are suitably anchored in rigid position, preferably by nut and bolt means, the bolts 39 of which are embedded in central portion 17 of base 11 with the upper or outer end portions of bolts 39 passing between bars 35. The outer ends of bolts 39 are threaded to receive nuts 41, and it is preferred to use clamping washers 43 on both sides of bars 3-5, such fitting over bolts 39. Spaced bars 35 also receive therebetween to mount, the head end portions of bolts 45 with the heads proper of bolts 45 engaging the lower edge of spaced bars 35. A channel member 47 is movably mounted in recess 37 in base 11 to move up and down in the recess as desired, to tension wires and/or cables 21. The sides of channel member 47, which is mounted in inverted position, fit over the sides of spaced bars 35 to receive same in slidable relation thereto. Bolts 45 pass up through holes 49 in the top of channel member '47 when mounted, and nuts 51 on bolts 45 position and maintain channel member 47 as desired relative to fixed bars 35. Bolts 45 are threaded on their upper end portions, so that by turning nuts 51 channel member 47 can be forced downwardly or released to move upwardly, as desired. A plate 53 is mounted on base 11 to cover recess 37 therein between the angle irons .19 which form the guide means for the mold member of the apparatus. This plate 53' preferably of steel then forms the upper surface of the base 11 over recess 37 in the central portion of the base which, as will be seen hereinafter, forms in operation a portion of the mold employed to form pre-stressed concrete beams. The vertically disposed deflecting

members

27 and 29 pass down through holes in plate 53 and corresponding holes in the upper portion of inverted channel member 47. The lower ends of these members 27 and 29' are threaded to receive nuts 55 which when engaged mount the deflecting assemblies to move with channel member 47. By this means upon tightening nuts 51, with nuts 55 engaged on

members

27 and 29 passing through the upper portion of channel member 47, the deflecting assembly members 31 and 38 in contact with wires and/ or cables 21 thereunder can be moved downwardly against the force of the tension of members 21 to place wire and/ or cable reinforcing members 21 under more tension. This has been found very satisfactory in operation.

A mold member at; having sides 6 2, a top 64, and a passageway 66 therethrough, and open in the ends and bottom is slidably mounted on base 11 to move therealong between guide means or angle irons 19. Mold member 60 in combination with base 11. between guides 19 forms the mold of the apparatus of my invention. Mold member '60 can be made of any suitable material, preferably iron or steel, and sides 62 thereof have inwardly projecting portions 68 which provide for a cross sectional shape of passageway 66 to form in operation a pro-stressed concrete beam of I-beam shape. Mold member 60 has open hopper means 70 in the top 64 thereof through which concrete is passed or poured during operation to make pre-stressed concrete beams. As one skilled in the art can see, this is very advantageous because a common or usual truck hauling ready-mixed concrete can back up or come alongside the apparatus to easily dump concrete through a delivery spout into lhopper 70 and thus into the mold of the apparatus. Of course, any suitable means and methods to introduce concrete through hopper 70 into the mold can be used, and if desired, a common overhead track arrangement can be provided for moving a hopper of concrete along the apparatus in dumping relation to mold member 60 and the hopper 70 thereof. In this connection I have found it convenient in some instances to provide common superstructure framework to support mold member 60 'and/ or a moving hopper of concrete supply, or mold member 6%? can be made heavy enough to operate properly without support.

In operation mold member 60 is slid along base 11, and cable 75 attached to mounting member 77in turn attached to mold member 60 has been found satisfactory and desirable to accomplish moving of mold member 60 relative to base 11. A winch 70 suitably mounted on right end member 13 has been found convenient to receive and wind cable 75 to move mold member 60. Any suitable powering means, such as motor 81, can be employed to wind winch 79 in operation.

The apparatus of my invention as depicted in FIG. 1 can be used to produce a single pre-stressed concrete beam or a plurality of pre-stressed concrete beams in series, with the reinforcing wires and/or cables 21 deflected by assemblies 25 as shown and being approximately longitudinal to the beam formed, the exception being at the end portions of base 11v where reinforcing members 21 project upwardly slightly as a result of deflection. When a plurality of beams are made in series by apparatus having a base 11 long enough, a bulkhead member 84 (FIG. 8) is preferably used and mounted on base 11 between angle iron guides 19' at one end or both ends of the space providing for the beams to be formed. These bulkhead means 84 have aperture means to receive wires and/or cables 21, such being indicated by dotted lines at 86 in FIG. 8. The wires and/or cables 21 hold the bulkheads 84 down in operation. After operation to form the concrete beams, the wires and/ or cables 21 are cut and the bulk heads removed from the apparatus. Apertures 86 can be placed in bulkheads 84 as desired, so that, if desired, wires and/ or cables 21 will pass up and down in relation to base 11 and so that they will have this position in the final beam formed by the apparatus in its operation, or apertures 86 can be placed and positioned 7 so that wires and/ or cables 21 will stay in approximately a straight line spaced from base 11 throughout substantially the length of base 11.

In FIG. 9 is shown another preferred specific embodiment of apparatus of my invention which is preferably used to produce a plurality of pro-stressed concrete beams in parallel, and in operation each of the parallel lines can produce a plurality of such beams in series. A base 11 and end members 13 like in the embodiment of FIG. 1 can be utilized, and the manner of operation and mounting of deflecting assemblies 25 can be the same as in the apparatus of FIG. 1. Angle iron guides 19 mounted on base 11 are employed the same as in the apparatus of FIG. 1. Of course, base 11 would be larger in width in this instance and guide member 19 would be spaced apart more widely. Also, deflecting assemblies 25 would be set and mounted in channel members 4-7 side by side, as would be the case with the bulkhead means 84 mounted on base 11, if such are employed, and they can be. Twin mold members 91, each being very similar to mold member 60 of the embodiment of FIG. 1 are mounted side by side in slidable relation to base 11, and in operation move along base 11 between angle iron guides 19. These mold members 9 1 have a common open hopper means 93 with divider means 95 to introduce concrete into both molds during operation, such molds formed by mold members 91 and the central portion of base 11 between guides 19. The mold members 91 are shaped inside the same as mold members 60 of the embodiment of FIG. 1, so that in operation they produce a I-beam shape of pro-stressed concrete member. Like mold member 60, they can be shaped to produce any shape of pre-stressed concrete beam desired. In this instance operating cable 75 is attached by a forked member 99 to mold members 91 so that they can be moved together along the length of base 11.

In operation to produce pre-stressed concrete beams by the method of my invention with either of the specific embodiments of my invention preferred and shown in the drawings, the mold members are positioned on base 11 at the end away from winch 79, and so that the mold members enclose the reinforcing wires and/or cables 21 stretched between end members 13. These reinforcing wires and/ or cables 21 then pass through the mold formed by the mold members and base 11, and underneath the Christmas tree-type deflecting assemblies, that is under the horizontal members or

arms

31 and 33 thereof, which deflect the wires and/or cables 21 to tension them desirably along with the tension placed upon them by stretching them between end members 13. Concrete is poured into the mold members (through hopper 70 or 93), and it flows into and fills the space within the mold members and comes into contact with the reinforcing wires and/or cables 21. It is prefererd to agitate the concrete within the mold members and this can be suitably done by a portable agitator stuck down into the concrete in the mold, the agitating member being vibrated to see that the concrete properly fills the mold and to eliminate entrapped air, and the like. In starting the operation, a period for the concrete set up is allowed, and when the concrete has set up enough to maintain its form in the shape produced by the mold, the mold member or members are moved by Winch 79 and cable 75. A portion of the resulting solidified concrete within the mold remains stationary and the

mold members

60 or 91 move out of contact therewith in the rear portion of the mold. Additional concrete is then introduced into the mold formed by the mold members and base 11 through

hopper

70 or 93, additional agitation is performed on the newly introduced concrete, and it is allowed to solidify in the manner of the first concrete introduced. The

mold members

60 or 91 are then moved further along base 11 and out of contact with another portion of concrete which has solidified in the mold. This new portion out of contact with the mold members then becomes an additional integral portion of a formed prestressed concrete member. Once the operation has been started, it can be continued in a continuous or semi-continuous operation until the mold member or 91 has traveled the complete operating length of base 11, length enough so that the remaining portion of the base can be used to move the mold members out of contact with formed concrete members for removal of the form members from base 11. The end of the beam member formed or the last beam formed in series can be established by using a bulkhead means 84 on base member 11 and held thereon by the tension of wires and/or cables 21. The formed pre-stressed concrete members are then cured the desirable amount, up to 96 hours in usual circumstances, and it has been found desirable to maintain tension on wires and/ or cables 21 during a substantial portion of this time. When the beams have cured sufiiciently for removal from the apparatus, the deflecting assemblies 25 are disassembled by removing nuts 51 from bolts 45, this allowing the removal of channel members 47 from recesses 37. The channel members are removed from

members

27 and 29 by removing nuts 55 therefrom. This then releases plates 53 for removal from the pre-stressed concrete beams formed on the underneath side. It is preferred to cut oil the ends of

members

27 and 29 flush with the face of the concrete beam formed and through which they project, and wires and/ or cables 21 are preferably cut off flush with the ends of the beams. The em bedded portions of deflecting assemblies 25 then remain in the pre-stressed beams along with wires and/or cables 21 to reinforce the beams. The pre-stressed concrete beams made by these preferred specific embodiments of the apparatus of my invention by the new method of my invention is shown in side elevation in FIG. 5, and identified by numeral 100. The cross section shape of this beam 100 of I-beam shape is shown in FIG. 7, as is the spacing and positioning of reinforcing wires and/or cables 21 therein. Of course, these wires and/or cables can be spaced and positioned as desired.

As will be evident to those skilled in the art, various modifications of my invention can be made, or followed, in the light of this disclosure and discussion, without departing from the spirit or scope of disclosure or from the scope of the claims. Specifically, beams, poles, pilings, and the like, of any desired shape and size can be made by the new method and means of my invention.

I claim:

1. Apparatus for making pre-stressed concrete structural beam members having prc-tensioned metal elongated reinforcing members substantially longitudinal therein and under great tension, comprising, in combination, an elongated and relatively smooth and flat base, a plurality of transversely extendng recesses in said base, end members rigidly secured to said base in mirror image relation with one of said end members at each of the end portions of said base, spaced and substantially parallel guide means secured to said base and extending longitudinally substantially the length thereof, each of said end members having means constructed to anchor end portions of a plurality of said reinforcing members stretched therebetween under great tension and in vertical and horizontal spaced relation, anchoring means, each of said recesses in said base having one of said anchoring means therein, each of said anchoring means including upwardly projecting bolt means, a plurality of permanently embedable deflecting assemblies, each of said assemblies including spaced vertical members and spaced horizontal members rigidly secured to said vertical members with each of said horizontal members constructed and positioned when said assemblies are mounted to receive and hold thereunder in deflected condition a plurality of spaced reinforcing members under tension to be embedded with said assemblies in concrete beams produced, a plurality of channel-shaped members, each of said deflecting assemblies having said vertical members thereof removably secured to said channel-shaped members and projecting upwardly therefrom, each of said transverse recesses in said base receiving one of said channel-shaped members therein with said deflecting assemblies thereon projecting upwardly therefrom and with said channel-shaped members being vertically adjustably mounted on said bolt means of said anchoring means to vertically adjust said deflecting assemblies, mold means comprising a mold member having sides, a top and a passageway therethrough and open in the end and bottom. portions and slidably mountable on said base to move therealong in guided relation to said guide means, said base forming the bottom of a mold in operation, said mold member having a hopper in the top to introduce concrete thereinto, constructed on its inside to shape concrete therein in setting to a concrete member of a desired shape and to receive through said passageway said plurality of reinforcing members when stretched between said end members and to receive said deflecting assemblies, Winch means mountable on one of said end members and having a cable therewith with said cable being attached to said mold member to move same substantially the length of said base during the molding process, said apparatus adapted when said plurality of reinforcing members are stretched and under pressure between said end members, deflected in contact with said deflecting assembly and passing through said mold member passageway to make a pre-stressed concrete member having said reinforcing members therein and having said deflecting assemblies therein by moving said mold member along said base and introducing concrete thereinto through said hopper means.

2. The apparatus of claim 1 wherein said mold is of shape to produce an I-beam, said horizontal members of said deflecting assemblies are three spaced members the lower one of which is substantially longer than the other two and said horizontal members being of size and positioned to receive and deflect four lower ones, two middle ones, and two upper ones of said reinforcing members, and said pre-stressed concrete members produceable by said apparatus are pre-stressed concrete I-beams with said reinforcing members in the lower half portion of said I-beams as produced.

3. The apparatus of claim 1 wherein said mold means comprises a plurality of mold members side by side in spaced relation with each of said mold members having sides, a top and a passageway therethrough and open in the end portions, and each of said mold members having open hopper means in said top to introduce concrete thereinto.

4. Apparatus for making pre-stressed concrete structural members having pre-tensioned reinforcing members therein under great tension, comprising, in combination, a base, a plurality of transversely extending recesses in said base, an end member at each end of said base, guide means with said base and extending substantially the length thereof, each of said end members having means constructed to anchor end portions of a plurality of said reinforcing members stretched therebetween under great tension and in vertical and horizontal spaced relation, anchoring means in said transverse recesses in said base and having upwardly projecting bolt means, a plurality of permanently embedable deflecting assemblies, each of said assemblies including spaced vertical members and spaced horizontal members rigidly secured to said vertical members with each of said horizontal members constructed and positioned when said assemblies are mounted to receive and hold thereunder in deflected condition a plurality of spaced reinforcing members under tension to be embedded with said assemblies in concrete beams produced, a plurality of channel-shaped members, said defleeting assemblies having said vertical members thereof removably securable to said channel-shaped members projecting upwardly therefrom, said channel-shaped members with said deflecting assemblies thereon projecting upwardly therefrom mountable in said transverse recesses in said base with said channel-shaped members vertically adjustably mounted on said bolt means of said anchoring means to vertically adjust said deflecting assemblies, mold means comprising a mold member having sides, a top and a passageway therethrough and open in the end and bottom portions and slidably mountable on said base to move therealong in guided relation to said guide means, said base forming the bottom of a mold in operation, said mold member having means in the top to introduce concrete thereinto, constructed on its inside to shape concrete therein in setting to a concrete member of a desired shape and to receive through said passageway said plurality of reinforcing members when stretched between said end members and to receive said deflecting assemblies, means attachable to said mold member to move same substantially the length of said base during the molding process, said apparatus adapted when said plurality of reinforcing members are stretched and under pressure between said end members, deflecting in contact with said deflecting assembly and passing through said mold member passageway to make a pre-stressed concrete member having said reinforcing members therein and having said deflecting assemblies therein by moving said mold member along said base and introducing concrete thereinto.

Equipment, February 1957, pages 138-140 and 149.

Hold Down Restrains, Concrete, September 1957, vol. 65, issue 9, page 60.

Hold Down Anchors for Pretensioned, Prestress Concrete, Superior Concrete Accessories, Inc., Franklin Park, 111., Dec. 2, 1957.