US3030687A

US3030687A - Method and apparatus for producing a monolithic concrete construction panel

Info

Publication number: US3030687A
Application number: US743597A
Authority: US
Inventors: Paul M Muspratt
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-06-23
Filing date: 1958-06-23
Publication date: 1962-04-24
Anticipated expiration: 1979-04-24

Description

April 24, 1962 P. M. MUSPRATT 3,030,687

METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL 8 Sheets-Sheet 1 Filed June 23, 1958 ATTORNEYS April 24, 1962 P. M. MUSPRATT 3,030,687

METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL 8 Sheets-Sheet 2 Filed June 23, 1958 w- INVENTOR Paul M Muspra/f K BY w m WW ATTORNEYS April 24, 1962 P. M. MUSPRATT 3,030,687 METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL Filed June 23, 1958 8 Sheets-Sheet 3 FIG. 3

FIG. 30

INVENTOR Paul M. Muspraff BY W MW ATTORNEYS April 24, 1962 P. M. MUSPRATT 3,030,687

METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL Filed June 23, 1958 8 Sheets-Sheet 4 K) k m 7 E 6 'llglamluwllll L m m A A A l I g mmmll-xcw Q 3 a m I 4 I} 0 I N f i f Q A A l I 0S V 0S Q A 0 :1 A o F I: l! E I -E I 9 k in 2 Q ET I H 0 I S I}. :1; A

{E IE i i: :2 n v 3 INVENTOR Paul M Musprah ma/AM ATTORNEYS MUSPRATT 3,030,687

April 24, 1962 M METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC 8 Sheets-Sheet 5 CONCRETE CONSTRUCTION PANEL Filed June 23, 1958 HUM/Hm FIG. I3

a mum/M G F INVENTOR Paul M Muspraf/ ATTORNEYS April 24, 1962 P. M. MUSPRATT 3, 30,687

METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL Filed June 23, 1958 8 Sheets-Sheet 6 A a: 1 2 A 8T- 3 1 '4 g 315i Q5 a I I Q5 it Q R; W M Z i INVENTOR Paul M. Musprah ATTORNEYS April 24, 1962 P. M MUSPRATT 3,030,687

METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL 8 Sheets-Sheet 7 Filed June 25, 1958 R4! mm Nf p M8 U M M w P BY I AiTORNEY-S April 24, 1962 P. M. MUSPRATT 3,030,687

METHOD AND APPARATUS FOR PRODUCING A MONOLITHIC CONCRETE CONSTRUCTION PANEL 8 Sheets-$heet 8 Filed June 23, 1958 ATTORNEYS lNV EN TOR Pau/ M Musprafl 3,030,687 METHUD AND APPARATUS FQR PRGDUCENG A MGNGLKTHEQ CQNCRETE CONTRUCTION PANEL Paul M. Muspratt, 329 /2 S. Broad St., Jersey Shore, Pa. Filed June 23, 1958, Ser. No. 743,597 A 3 Ciaims. (U. 2541).

This invention relates to the art of building construction, and more particularly to the method and apparatus for producing a monolithic and internally cross-cored construction panel.

This application is a continuation-in-part of copending application Serial No. 307,045, filed August 29, 1952, now Patent, Number 2,840,353.

Broadly speaking, concrete constructions for use in connection with walls and ceilings and the like may be made in two ways; i.e., they may be either poured in place or they may be prefabricated. V I

The present invention relates to the methodand apparatus for molding a prefabricated concrete panel construction which, for themost part, is employed in connection with walls and ceilings or the like and which, may be readily formed without the use of internalreinforcement. The present invention also provides an internally cross-cored panel construction having an eifective or resulting specific gravity such that the same may be handled readily without any fear that the panel will break or crack under. its own weight.

Where concrete slabs are used in connection with the construction of walls, the strength of theconcrete in a vertical directionis generally sufficient to withstand whatever loads may be imposed upon it without requiring, at the same time, additional internal reinforcements such as steel rods and the like. Therefore, when a concrete wall is formed by pouring the same in place, i.e., by using a vertical form located Where the wall is finally to be positioned, such internal reinforcements are generally un necessary. However, where the -wall isto be formed from prefabricated wall panels, and where the panels are of any considerable size, it is necessary to provide internal reinforcements within the panel, because, in the handling of the panel prior tothe setting of the same in its final vertical position, there is always a danger that the panel will break or fracture under. its own weight.

As indicated above, the panel produced by the method and apparatus of the present invention is provided; with longitudinal and transverse intersecting cores which result in a product having a low density. Even in the absence of internal reinforcements, it is possible to handle the panel of the present invention, in a horizontal or vertical plane, without the attendant disadvantage that the same might crack or break under its own weight.

The method and apparatus for carryingfout the present invention includes a horizontally arranged and substantially rectangular form or mold into which the concrete mass is. poured. A plurality of substantially parallel and spaced longitudinal members (preferably cylindrical in form) extend longitudinally for the full length of the form. A plurality of shorter members, arranged in spaced and parallel relationship with each other, extend transverse to and through the longitudinal members described above. In order to effect this intersecting relationship, each of the longitudinal members is provided with a plurality of transverse holes such that each transverse mentber 'will extend completely across the form and through corresponding aligned holes in all of the longitudinal members.

In constructing the cross-cored concrete panel of the present invention, the side and end walls of the form are first set up, generally on a pallet, which constitutes the bottom of the form. Then the longitudinal members are Patent 3,030,687 Patented Apr. 24, 1962 inserted into the form so as to pass through corrflsponding holesin the opposite end walls of .thefonnf Nexftffthe transverse'members are inserted through holes in? one side wall, through aligned holes of the longitudinal mom bers and through holes in the opposite sidewall of'th form. After all ofthe longitudinal and transversernembers have been thus assembled, concrete, preferably in the form of a dry-mix, ispouredlinto the moldso as .to cover, completely the transverse andtlongitudi nal 'mer'n bers inside the form. Thereafter, the form, or the longi-' tudinal andtransverse members, or both. the ffori'n arid the members, are vibrated such that the a dry minwill flow and spreadits elf into all of the voids in theffor-m; The vibration is continued for a short periodoftim to insure the thorough mixing and distribution ofthe con crete mass throughout. The vibration is stopped, and thereafter the transverse members are withdrawn; After. all of. the transverse members have beenwithdra'wmthe longitudinal members are withdrawn. The sides; of, the form are thenremovedand the resulting concrete'mass is allowed to reach its finalsetcondition on the pallet.

Although it is preferable to remove the longitudinal andtransverse members as soon as possible, it maybe desirable, in some instances, tofwait for a short period of time after the' cessation ofvilrzrationsv to commence fremovalfof. the members; However, anyevent, these members must be removed before the concr efreaehes its final setcondition. inaccor'dance with one modification of the present in; vention, as will appear hereinafter, itisfpossibletoachieve a panel. structure where. the centralzone is provided with an insulating layer. This is accomplishedby pouring the concrete into the mold at a level slightly b'elow the cell'- tral longitudinal axes of. the cross members. Atthi's'stage of the proceedings, a plurality of. insulating blocksjof sufficient. size to, fit into the rectangular spaces between the cross members are suspended on a framej orgrid so as to lie in the proper. positions. The initiallayer of c' oncrete is preferablyvibra-ted beforethese blocks are put into position. After these blocks have been put into position, the mold is filled. with'concrete and the entire mass is vibrated, arid the same procedure is followed there after as described above.

According to another modif cation of the present invention, it is possible to provide a building. Palm construction of the type described above wherein there are a plurality of holes leading from the longitudinal bores to one of the facesof; the panel. In'this connection, a panel of such a description may be used for a ceiling, and "theholes may be used in combination with, the internal cores to withdraw noxious fumes from the room; alternatively, it is possible to force water through the cores and through the holes, in the manner of a sprinkler system, in the event of fire. The method of constructing this type of building panel is substantially the same as the first method with the exception that conically shaped Wax pieces, supported on a suitable metallic grid. structure, are positioned over the longitudinal 'rnembers before the concrete i:s 'p rod into place. In the course of the curingjoperatign, where the temperature may reach 9,0, or above, the wax cenes will melt, leaving the resulting. holes referred to above.

As will hereinafter appear, another modification of the present invention permits the separation or subdivision of a r Pan to. two or m r m le P n l Therefore, it is a principal object of the present invention to provide a method and apparatus for molding a monolithic concrete panel structure having a plurality of longitudinal coresor bores of a given cross-sectional size extending in spaced and parallel relationship fo'rthe length of the panel and a plurality of transversecores or bores arrangedjin'spaced, parallel relationship with each other and intersecting the longitudinal cores, the cross-sectional size of the transverse cores being smaller than the corresponding cross-sectional areas of the longi-.

tudinal cores.

It is a further object of the present invention to provide a method and apparatus of the type described above which will permit the construction of the above described wall panel in different and convenient lengths.

It is is a. still further object of the present invention to provide a method of molding a wall panel of the type described above, constructed monolithically, but wherein one of the outer surfaces is formed from a slab of stone or the like.

Other and further objects and advantageous features of the present invention will hereinafter more fully appear in conection with a detailed description of the drawings in which:

FIGURE 1 is a view in perspective of the apparatus employed for constructing the panel of the present invention;

FIGURE 2 is a fragmentary plan view of the structure shown in FIGURE 1;

FIGURE 3 is a side elevation, partly in section, of the means employed for extracting the longitudinal and transverse members, as shown in FIGURE 1, the part in section corresponding to section line 33 of FIGURE 1;

FIGURE '4 is an elevation partly in section as the same would appear taken along section line 4-4 of FIGURE 3;

FIGURE 5 is a view of the roller element shown in FIGURES 1-4 inclusive; g FIGURE 6 is an elevation of one of the long side walls or'plates of the form showing that surface which faces the interior of the mold;

"FIGURE 7 is a sectional view taken along section line 7-7 of FIGURE 6; 7

FIGURE 8 is an elevation of one of the shorter or end walls or plates of the form showing that portion which faces the interior of the mold;

1 1 FIGURE 9 is a section view taken alongsection line 9 -9 of FIGURE 8;

FIGURE 10 is a longitudinal section view through one in FIGURE 21;

FIGURE 24 is a perspective (with parts broken away) of the concrete panel construction produced according to the present invention;

FIGURE 25 is a section through one corner of the panel as it would appear taken along line 2525 of FIG- ofthe longitudinal members employed in the apparatus of the present invention;

FIGURE 11 is across-sectional viewof one of the longitudinal members as taken along section line 1111 in FIGURE 10; 7

FIGURE 12 is an elevation, partly in section, of one of the transverse members employed in the apparatus of the present invention; 7

FIGURE 13 is a view similar to FIGURE 6 showing a modified form of one of the longer side walls of the form; I r

FIGURE 14 is a sectional view taken along section line 14-14 of FIGURE 13 showing the relationship between an insertable element and a slot in the upper edge of the side wall of the form; a

FIGURE 15 is a perspective of the insertable element shown in FIGURE 14; V

FIGURE 16 is a sectional view taken along section line 1616 of FIGURE 13 showing the relationship between another insertable element and a slot in the lower edge of the side wall of the form;

FIGURE 17 is a perspective view of the insertable element shown in FIGURE 16;

FIGURE 18 is a view similar to the central portion of URE 24;

FIGURE 26 is a perspective view of a modified form of the panel construction where the central zone thereof is provided with an insulating layer; 7

FIGURE 27 is a perspective view of the insulating blocks and supporting structure therefor which are used in the construction of the block shown in FIGURE 26;

FIGURE 28 is a section view as it would appear taken along section line 2828 with one of the longitudinal cores still in position, and showing the relationship between one of the insulating blocks, a portion of the frame structure for supporting the same, and one of the longitudinal members on which the frame structure is caused to rest;

FIGURE 29 is a perspective view of a modified form of the block shown in FIGURE 24 wherein a plurality of holes communcate with one face of the block and with the longitudinal cores;

' FIGURE 30 is a perspective view showing the apparatus which may be employed in the construction of the block shown in FIGURE 29; and

FIGURE 31 is a perspective view, similar to FIGURE 24, showing a modified form of the panel wherein one of the faces is formed from a slab of stone or the like. Referring to the drawings in detail, FIGURE 1 shows a form or a mold comprising longitudinally extending side walls or plates 1 and 2 and a pair of parallel spaced end walls or plates 3 and 4, suitably arranged in rectangular fashion on top of a bottom plate or pallet 5. Each end plate (see FIGURE 8) is provided with a plurality of spaced circular holes 6 such that the holes in the end plate 3 are equal in number and in alignment with the corresponding holes in end plate 4. A plurality of longitudinally extending tubular members 7, which in the form shown in the drawings are hollow elongated cylinders; extend through the form and through the aligned holes 6 in the end plates 3 and 4. e

The side plates 1 and 2 (see FIGURE 6) are provided with a plurality of circular holes 8 which are greater in number and smaller in size than the holes 6 in the end plates 3 and 4. A plurality of transverse tubular members 9 also in the form of hollow cylinders extend through the form and through the oppositely aligned holes8 of the side plates 1 and 2. It also should be evident from the consideration of FIGURES 1, 2 and 3 that these transverse tubes 9 also extendthrough aligned openings in the FIGURE 13, showing the upper insertable element re'-,

knife elelongitudinal tubes 7.

, As best shown in FIGURES l0 and 11, each longitudinal member 7 is provided with a plurality of oppositely aligned

openings

10, 10 into whicha cylindrical sleeve 11 may be inserted; The inner diameter of each sleeve 11 is equal to the outer diameterof the transverse tubular member 9 Thus, the sleeve 11 serves to provide throughopenings for the transverse tubes 9 and, at the same time, serves to seal off the interior of each longitudinal tube 7 such that later on, during the molding operation, no concrete can seep'into the interior of the longitudinal member.

Each longitudinal member 7 is provided with an insertable plug 13 having a tapered end 14 which facilitates the insertion of each longitudinal member into the form through the holes 6 of theend plates 8 and fl. Also, each longitudinal member 7 is provided with a plurality of vibrator elements-15, all ofwhich are connected to, and held in position by, a conduit 16 which extends lengthwise inside each longitudinal tube 7 and which is connected to, a source of pneumatic. pressure (not shown). These vibrator units 15 are essentially of conventional nature, and hence the internal, details of these members are not shown; however, the opposite ends of each of these vibrators are caused to bear against the inside of the longitudinal tube 7 such that when the source of pneumatic pressure is applied, these ends will vibrate against the inside of the longitudinal member and thus transmit vibrations to the longitudinal members and to the transverse members which pass throughthem. As shown in FIGURE 10, the individual vibrator units 15 are relatively angularly positioned with respect to one another throughout the length of the longitudinal tube 7 so as to distribute the vibrations uniformly around the periphery of the tube. For example, the left-hand vibrator 15 is shown in the verticalposition; the central vibrator element is shown at a 45 angle and the right-handvibrator element is shown in a substantially horizontal'position.

In FIGURES 1 and 3, there is shown a device which is employed for extracting the tubes from the form. It should be understoodthatthis device is merely illustrative of one type of mechanism which might be employed and should not be considered as limiting as far as the present invention is concerned. This extractor includes apair of spaced horizontal arms 19 and 20 at the top of which a winch 21 is mounted. Adjacent the forward end of these arms 19 and' 20, there is a bracket 22 including apair of downwardly projecting

legs

23 and 24. Adjacent the rear end of these arms 19 and 2.0,there is another bracket 25 including a pair of'spaced

vertical plates

26 and 27. A guide roller 28' is suitably mounted for free rotation between the two legs. 23 and 24 adjacent the bottom end thereof. Another roller 28 is mounted for free rotation between the two

plates

26 and 27 adjacent the lower ends thereof and in alignment with the first mentioned roller 28. Each roller 28 is provided with a pair of curved surfaces 29. and 30 of different radial dimensions and designed for use in the extraction of the transverse tubes 9 and the longitudinal tubes 7, respectively.

The arms 19 and 20 at their extreme right-hand ends (as arm 19 appears in FIGURE 3) are provided with a pair of vertical slots 31 which are adapted to fit over a guide rail 32 extending on the outside of the side plate 1. The

legs

23 and 24 are provided with a pair of horizontally extending projections 33 which abut against the vertical outside surface of longitudinal side plate 1 so as to hold the extractor assembly in a substantially horizontal position. A pulley 34 mounted on a shaft 35 is arranged for free rotation between the

vertical plates

26 and 27. A cable 36 passes around the pulley 34 and to the winch 21. The other end of the cable is hooked as at 37 and is adapted to pass around a suitable loop 38 at the left-hand end of the transverse tube 9. Thus, as it appears in FIG- URES 1 and 3, if the winch 21 is turnedin the proper direction, the cable 36 will pull the transverse tube 9 toward the left and away from side plates 1 and 2 and the longitudinal tubes, 7, the transverse tube 9 riding over the curved surfaces 29 of the pulleys 28.

The extractor assembly can be moved along the slide rail 32 so as to pull each of the transverse tubes 9 individually from the assembly shown in FIGURE 1. Also, this extractor assembly can be mounted on the slide rail 40 attached to the end plate 3, so that the longitudinal tubes (after all of the transverse tubes 9 have been removed) may be caused to slide over the curved surfaces 30 of the rollers 23. in this instance, however, the cable 36 will be attached to separate cables 41, each of Which extends along the upper surface of a corresponding longitudinal tube 7 and in a suitable depression 42 provided in the upper surface thereof. The cables 41 are provided at their left-hand ends (as they appear in FIGURE 1') with hooked portions 42 which hook around the ends of the longitudinal tubes 7 or, wherethe plugs 13 are employed, into suitable holes or spaces provided in theplugs or between the plugs and the tubes.

Each of the side plates 1 and 2 is provided with a longitudinally extending, projection 45 which is formed in the shape of a dovetail and which, as will appear hereinafter, will provide corresponding dovetailed grooves in the, sides of finished concrete panel. The end plates 3 and 4 are provided with similar projecting bars 46 which serve to make dovetailed grooves in the ends of the final concrete product. It should be understood that one or more of the

elements

45 or 46 might be provided on the side and end plates, respectively, andthey might be arrangedsuch that one is at the top and one atthe bottom, or with two at the topand one at the botom, Q11 in any desired combination.

The panelproduced according to a preferred form, of this invention is shown

inpFlGURES

24 and 25; asub stantially rectangular block 50 is shownas havinga plurality of larger longitudinal bores 51 and a plurality of smaller transverse bores 52 which extend at right angles and in intersecting relationship with the longitudinal bores 51. The longitudinal axes of the longitudinal bores and the transverse bores preferably lie in thesame horizontal plane; also the longitudinal bores are larger in crosssection than the transverse bores 52,. In practice, it will be desirable to make the size of the transverse bores 52 as large as possible relati've to the size of the longitudinal bores 51, Howeven in view of the fact that the longitudinal tubes 7 must be constructed in such a way. as to. have transverse holes therethrough, which holes accommodate the positioning of thetransverse tubes 2, it should be appreciated that the sizes. of these openings will be limited by the amount or degree to which these longitudinal tubes may be permissibiy weakened by the occurrence of these interruptions in the structure of the longitudinal tube. The block shown in FIGURE 24 is also provided with a dovetailed groove 53 which extends completely around the edgesv of the block.

In order to construct the block shown in FIGURE 24, the horizontal, plate or pallet is, located in. a suitable posi tion for carrying out the operations involved. Theside plates 1 and 2 are placed in'vertical position adjacent the longitudinal edges of the pallet, and are secured thereto by means of suitable, clamping means (not. shown). Thereafter the end plates 3 and 4 are placed in position and are secured also, by means of suitable clamping means, (not shown). The longitudinal tubes or corm 7 are next inserted and so positioned that the cross holes therethrough are in alignment for the subsequent positioning of the transverse tubes, or cores 9. Thereafter the transverse tubes 9 are insertedin position, and the entire structure takes on thelappearance shown in, FIGURE 1.

A suitable concrete mix, preferably the s d-called drymix, is, poured into the mold. If this; operation takes pl ce n a p ant f r m kin these con r e la hen vibrations may be imparted totghe mold through theme.- diurn of a v b ingta le p n h qh h na let 5 m y be mounted. Otherwise, where this operation takes. place out on the job, vibration may be imparted to the system by means of thev vibrating elements 15' located within the longitudinal tubes 7. In any event, vibration is imparted to the concrete mix, and the same is caused toflow, filling in all the voids in the mold and around the tubes. After the concrete has been vibrated for a sufficiently long period of time, the vibration is stopped. At a. suitable time thereafter, and preferably before the concrete commences to take on its final set condition, the transverse tubes 9 are removed. After all of the transverse tubes are removed, the longitudinal tubes 7 are then removed. The side plates 1 and 2 are now removed and thereafter the end plates 3 and 4. The pallet 5 with the concrete block thereon (in uncured condition) may be placed to one side where the concrete block may be allowed to set; on the other hand, the pallet 5; and block thereon may be placed in a drying oven if desired.

FIGURE 26 shows 'a modified form of the blockshown in FIGURE "24. In thisin'sta'nc'e, the block 60 havinglongitudinal bores 61 and transverse bores 62, as well as dovetailed groove 63, will be identical in shape to the block 50 shown in FIGURE 24; however, the block 60 is provided with an internal layer 64 of insulating material such as foamed glass, or the like. Preferably, this intermediate layer 64 will be symmetrically arranged with respect to the horizontal plane passing midway through the thickness of the panel.

The method for producing the block shown in FIGURE 26 will be similar to that employed for making the panel shown in FIGURE 24 except that the method will take place in two steps or stages. First of all, the form and the crossed tubes will be set up in the same manner as previously described in relation to the production of the panel shown in FIGURE 24. However, only sufiicienit concrete will be poured into the form to approach a level slightly below the central axes of the tubes. At this point, a pluralityof blocks made from the foamed glass material will be inserted into the spaces between the crossed tubes. These blocks of foamed glass material, generally designated by the reference numeral 65 in FIGURE 27, are shown as being of varying shapes which represent the different positions these blocks are to occupy in the various spaces provided between the crossed tubes. These blocks 65 are mounted on the ends of vertical studs 66 which project downwardly from, and are attached to, a frame structure consisting of longitudinal rods 67 and transverse rods 68.

Thus, as indicated above, after the first half of the required amount of concrete has been poured into the mold and after the same has been vibrated to cause the same to flow and fill the voids in the lower half of the mold, the blocks 65 and their supporting grid are placed into the mold or form such that the blocks 65 come to rest on the top surface of the concrete just poured. As shown in FIGURE 28, the transverse rods 68 will rest along the tops of the longitudinal tubes 7. Thereafter, the remaining quantity of concrete is poured into the mold on top of the blocks 65; the system is caused to vibrate such that the concrete will flow and fill the voids in the upper half of the mold. After this, the vibration is stopped, the transverse tubes are withdrawn, the longitudinal tubes are withdrawn, the side and end plates are removed, and the resulting structure on the pallet side is placed to one side so as to allow the concrete in the panel to set. In this connection, it should be noted that the grid structure consisting of the cross members 68, longitudinal members 67 and the studs 66 form a permanent part of the conorete panel 60 shown in FIGURE 26.

Another modification of the panel shown in FIGURE 24 is also shown in FIGURE 29 where the concrete panel 70 is provided with longitudinal bores 71, transverse bore 72 and a dovetailed groove 73in the same manner as described in relation to the prior embodiment. However, in the panel illustrated in'FIGURE 29, there are provided a plurality of holes 74- which extend from the upper face (as shown) downwardly and into communication with the longitudinal bores 71. The apparatus employed for producing the block shown in FIGURE 29 is illustrated in FIGURES 30 and 31.

In FIGURES 30 and 31, there is employed a horizontal frame or grid consisting of longitudinal rods 75 and transverse rods 76. Attached to the transverse rods 76 are a plurality of comically shaped wax plugs 77 which are spaced apart from one another a distance equal to the center-to-center distance between adjacent longitudinal tubes. Thus the grid structure is placed on top of the apparatus shown in FIGURE 1 such that the transverse rods 76 lie on top of the longitudinal tubes 7, as shown in FIGURE 30. After the grid structure has been positioned above the longitudinal tubes 7, concrete is poured into the mold until the level of concrete is at, or slightly below, the level of the upper ends of'the conically shaped plugs 77. Here again, the grid structure composed of cross rods 75 and-76will form a permanentpartof the resulting panel structure.

After the concrete has been poured to the level described above and after the form has been vibrated a s-uflicientlength of time, the sides of the form and the crossed tubes are removed in the same manner as described above in relation to the other embodiments. The

. panel is set aside until the cement or concrete hardens sufiiciently, after which the panel is placed in a curing oven where the temperature reaches approximately 90 F. or even higher. At this temperature, the wax cones 77 will melt leaving the voids or conically shaped holes 74 in the resulting end product. Thus, if the panel shown in FIGURE 29, or a plurality of such panels, is inverted and used in connection with a ceiling structure, it is possible, by placing a draft in connection with the crossed bores of the panel, to withdraw gasses or noxious fumes from a room or given area. Otherwise, with the panels still used in the same relationship in a ceiling structure, it is possible, under given conditions, to force water through the crossed bores so as to stimulate a sprinkler system in the event of tire.

The embodiment shown in FIGURE 32 is a modifica tion of the panel shown in FIGURE 24 where one of the surfaces, i.e., the upper surface as shown in FIGURE 32, is a slab of stone or other decorative material which is to be used as the exposed (inner or outer) facing for a given wall panel. As shown, this panel 80 includes longitudinal bores 81, transverse bores 82, and a dovetailed groove 83, and, in this sense, is substantially the same in form as the panel shown in FIGURE 24. However, a slab of stone 84 forms the upper surface of the block as shown.

In constructing the block shown in FIGURE 32, the slab of stone 84 is preferably placed face down on top of the pallet 5 before the sides 1 and 2 and end plates -3 and 4 are positioned and before the longitudinal tubes 7 and the transverse tubes 9 are placed in position. After this, the formation of the panel is substantially the same as that described in relation to the formation of the panel shown in FIGURE 24. Thus, the method of making the block shown in FIGURE 32 involves a single molding operation, and, in this sense, the resulting product can be considered as an essentially monolithic structure, even though one of the surfaces may be composed of .a material which is different from the main body of the panel. As indicated heretofore, the various dovetailed grooves shown in the drawings may be employed in greater number than is illustrated, and the actual number employed will be essentially a matter of choice or design. However, when assembling two or more panels, where mortar is placed in opposing dovetailed grooves of adjacent panels, the relationship is such as to assist in securing the panels together in a firmer relationship.

FIGURES 13 to 23, inclusive, relate to embodiments and variations of the form or mold, especially side plates 1 and 2, where it is desired to produce a resulting concrete panel which can be subdivided into a plurality of smaller panels. For this reason, the side plate 2' is provided with a plurality of narrow vertical slots adjacent the upper edge thereof, each slot 90 being adapted to receive an insertable elongated bar 91, as best shown in FIGURE 15. The slot 90 and the bar 91 are provided on their corresponding vertical mating portions with interfitting grooves 92 and projecting portions 93, respectively.

Similarly, adjacent the bottom edge of the panel 2' there are a plurality of wider vertical slots 96 which are adapted to receive the slidable plates 97, as best shown in FIGURE 17. The slot 96 and the insertable plate 97 are provided, along their corresponding vertically mating portions, with inten'itting grooves '98 and projections 99, respectively. In connectionwith the illustrations shown in FIGURE 13, it should be noted that the dovetailed bar .45 is not continuous throughout its lengtlnbut is provided 9. with interruptions 100 adjacent the locations of the slots 96. These interruptions are. symmetrically arranged in relation to the slots but are .of lesserwidth. The insertable plate shown in FIGURE 17 is providedv with a dovetailed bar 101 which is equal in length to the'distance' of the interruption'100 so that,.as shown lII-iF-IGURE16, when the plate 97 is in. its proper position the dovetailed bar 45., together with the. shorter bar 101,. constitutea' continuous dovetailed member along the-length of the side plate 2'.

When it is desired to. form a block or panel whieh'will permit the. separation or division of a larger panel into a plurality of smaller panels,.thebars 91' and plates" 97 corresponding to the desired location of the pointof division are removed from the opposite side plates of' the form. Another insertable plate 103-having rounded'side projections 99 and beingotherwise similar to the insertable plate 97 is inserted into the slot 96, as-shown in FIGURES l8'and 19. Each insertable plate 103 is-provided with a'central aperture 104 formed by a vertical slot 105" and pair of oppositely, projecting.dovetailedslotsJ106, as best shown in FIGURE 20. Thus, at the location of the desired' point of separation, the opposite slots 90 of the side plates will be unoccupied and the opposite slots 96 will each be occupiedby a plate substantially the same as'plate 103, shown in FIGUREZO.

The double'knife structure shown in FIGURES 21-23, inclusive, is adapted to be employed in conjunction with the structure shown in FIGURES 18-20, inclusive. Thus, there is shown a vertical bar 110 to which is attached a horizontally extending and relatively thin blade 111. This blade is substantially equal in thickness to the width of each slot 90 and is adapted to pass through the opposite unoccupied slots 90 in the opposite side plates of the form. Also attached to the vertical bar 110, adjacent the lower end thereof, and in parallel relationship with the blade 111 is another similar blade 112; however; the blade 112 is provided with a pair of longitudinally extending bars 113 which are each shaped in the form of a dovetail. The width of the central web portion 112 of the lower knife blade is substantially equal to the width of the vertical slot 105 of the aperture 104; also, the size and locations of the dovetailed bars 113 are such as to fit into the corresponding dovetailed openings 106.

Thus, when it is desired to form a point of separation in a given panel structure, the opposite side plates are arranged as shown in FIGURE 18 and the structure shown in FIGURE 21 is-inserted through one side plate so as to pass completely through the form and through the opposite side plate. The knife blades are preferably inserted before any concrete is poured into the form. Also, the knife blade is generally removed at the same time that the transverse tubes 9 are removed. Since the separation between the lower edge of knife blade 111 and the upper edge of knife blade 112 is only slightly larger than the diameter of one of the longitudinal tubes 7, it will be appreciated that the vertical openings formed in the concrete panel, as a result of the positioning of the knife blades therein, will be practically continuous when considered in relation to a vertical plane passing through these openings. Thus, when the concrete panel has hardened, it is a relatively simple matter to fracture the block or panel along the line of separation provided by the knife blades. Also, it should be evident that the bars 113 of the lower knife blade 112 will provide dovetailed grooves in the same manner as described in relation to the dovetailed bars 45 and 46.

Although the concrete employed in the product and method of the present invention has not heretofore been described in particular reference to its density, it should be understood that a concrete having a high density might be employed by itself, or, on the other hand, a concrete having a low density might be employed by itself. Furthermore, the method of the present invention permits the formation of a monolithic concrete panel having two layers-of-concretehaving different densities; this re-.

sult maybe achieved by pouring a first layer of heavy con-- creteinto' the mold" (employing the required vibration) and by; pouring a'second .layer- (before the first layer sets) procedure is followed as explained abovewith regard to the prior embodiments.

Althoughv the dovetailed bars 45 and 46 have been shown, for the sake of'sirnplicity in explanation, as being integralwith the side plates 1 and 2 and. the end plates 3 and 4,- respectively, it istactuallypreferred.to have these elements in" the form of separatev bars Which'can be removed in the same manner as the longitudinal and transverse tubes. This will simplify the removal of the side and end plates which may then be simply removed by. sliding; movement: in any desired direction.

In the appended claims, the terms concrete or concrete mass relate to concrete initially in the form of a dry-mix as defined above.

Whereas the present invention has beendescribed in particular relation to the illustrations shown inthedrawings, it should be understoodth'at other and further modifictaions, apart fi'om those shown or suggested herein, may be made within the spirit and scope of this invention.

What is claimed" is:

1. A method of'forming a monolithic concrete construction panel comprising constructing a rectangular form with bottom, side and end walls, passing a plurality of spaced parallel and longitudinal tubular members horizontally through the end walls of said form, each of said longitudinal members being of substantially uniform cross section throughout its length, passing a plurality of spaced parallel and transverse tubular members horizontally through the side walls of said form and transversely through said longitudinal members, each of said transverse members being of substantially uniform cross section throughout its length, depositing a concrete mass in said form and around said longitudinal and transverse members, applying a plurality of direct vibrations against the insides of said members within said form at spaced and angularly related positions along the lengths of said members so as to distribute vibrations uniformly around the peripheries of said members and so as to vibrate said mass for a suitable period of time, stopping said vibration, axially withdrawing said transverse members and axially withdrawing said longitudinal members from said mass prior to the time that said mass sets.

2. A method of forming a monolithic concrete construction panel having a slab of stone forming one surface of the panel and being bonded to the concrete thereof comprising constructing a rectangular form with bottom, side and end walls, placing a slab of stone face down against the bottom of said form, passing a plurality of spaced parallel and longitudinal tubular members horizontally through the end walls of said form, each of said longitudinal members being of substantially uniform cross section throughout its length, passing a plurality of spaced parallel and transverse tubular members horizontally through the side walls of said form and transversely through said longitudinal members, each of said transverse members being of substantially uniform cross section throughout its length, depositing a concrete mass in said form and around said longitudinal and transverse members, applying a plurality of direct vibrations against the insides of said members within said form at spaced and angularly related positions along the lengths of said members so as to distribute vibrations uniformly around the peripheries of said members and so as to vibrate said mass for a suitable period of time, stopping said vibration, axially withdrawing said transverse members and axially withdrawing said longitudinal members from said mass prior to the time that said mass sets.

3. Apparatus for producing a monolithic concrete construction panel comprising a form for receiving a poured concrete mass, said form including a substantially rec-' tangular and horizontal base plate, a pair of spaced parallel side plates secured to said base plate in vertical position adjacent the longitudinal side edges of said base plate, and a pair of end plates arranged in spaced and parallel relationship and being secured to said base plate adjacent the side edges thereof, said bottom, side and end plates defining a space having a rectangular horizontal cross section; a plurality of horizontal elongated tubular members extending in spaced and parallel relationship through said form; each of said horizontal members being of substantially uniform cross section throughout its length; and a plurality of vibrators mounted within each of said members, said vibrators bearing directly against the inside of said members and being relatively angularly positioned with respect to one another along the length of each member so as to distribute vibrations uniformly around the peripheries of said members.

References Cited in the file of this patent UNITED STATES PATENTS Day July 8, '1930 Miller Mar. 29, 1932 Jackson July 19, 1932' Sofensen Nov. 29', 1932 Cahill Apr. 25, 1933 Straub Jan. 15, 1935' Jackson Ian. 15, 1935 Staples Nov. 5, 1935 Deutsch Mar. 5, 1940' Brimhall July 2, 1940 McKenzie Dec. 2, 1941 Baily Aug. 11, 1942 Rogers et a1 Oct. 20, 1942 Hutchinson Aug. 29, 1944 Cuypers Feb. 21, 1950 Wissinger Sept. 26, 1950 Tomlinson Feb. 13, 1951' Eusner May 8, 1951 Johnson Feb. 24, 1953 Terrell Feb. 2, 1954' Briggs Feb. 15, 1955 Livingston et a1 Sept. 13, 1955 Johnson Jan. 31, 1956 FOREIGN PATENTS Australia Feb. 7, 1952' France May 30, 1932