US3751201A

US3751201A - Apparatus for casting slab-faced panels

Info

Publication number: US3751201A
Application number: US00254439A
Authority: US
Inventors: P Kelsey
Original assignee: Susquehanna Corp
Current assignee: Susquehanna Corp
Priority date: 1970-06-23
Filing date: 1972-05-18
Publication date: 1973-08-07
Anticipated expiration: 1990-08-07

Abstract

A casting box having at least one vacuum line connection through its floor is provided with a laminated insert plate which includes a resilient upper layer provided with one vacuum line opening for each slab, and which incorporates conduits extending from the openings to communication with the casting box floor. A placement grid having individual cells for receiving individual slabs is received in the casting box on the insert plate upper layer. After a slab has been placed in each cell a heavy seater is lowered onto the slabs to force them into sealing contact with the insert plate resilient upper layer and a vacuum is drawn through the casting box floor to hold the slabs so tightly against the insert plate resilient upper layer that the layer bulges up between adjacent slabs. The seater is removed; then the placement grid is withdrawn with the assistance of removable lateral shims and a settable composition such as concrete is poured into the casting box upon the slabs. The panels so formed have slabs set therein with simulated semi-flush concave joints. A modified device for production of panels faced with slabs on both sides is also disclosed.

Description

.1 1 WWW United States Patent [1 1 Kelsey APPARATUS FOR CASTING SLAB-FACED PANELS Paul -filflz. PFlfiLBFEEaFlE;

Assignee: The Susquehanna Corporation,

, Alexandria, et...

Filed: May 18, 1972 Appl. No.: 254,439

Related US. Application Data Primary Examiner.l. Spencer Overholser Assistant Examiner-Richard Bernard Lazarus Attorney-Cushman, Darby & Cushman 3,751,201 Aug. 7, 1973 A casting box having at least one vacuum line connection through its floor is provided with a laminated insert plate which includes a resilient upper layer provided with one vacuum line opening for each slab, and which incorporates conduits extending from the openings to communication with the casting box floor. A placement grid having individual cells for receiving individual slabs is received in the casting box on the insert plate upper layer. After a slab has been placed in each cell a heavy seater is lowered onto the slabs to force them into sealing contact with the insert plate resilient upper layer and a vacuum is drawn through the casting box floor to hold the slabs so tightly against the insert plate resilient upper layer that the layer bulges up between adjacent slabs. The seater is removed; then the placement grid is withdrawn with the assistance of removable lateral shims and a settable composition such as concrete is poured into the casting box upon the slabs. The panels so formed have slabs set therein with simulated semi-flush concave joints. A modified device for production of panels faced with slabs on both sides is also disclosed.

ABSTRACT 10 Claims, 9 Drawing Figures C C c m 4 60 62 mew-wea es llRl-VE I66 (/MVL .7704

APPARATUS FOR CASTING SLAB-FACED PANELS This is a division, of application Ser. No. 49,152 filed June 23, 1970.

BACKGROUND OF THE INVENTION The background of the slab-faced panel art is discussed -extensively in my copending application Ser. No. 18,173, filed Mar. 10, 1970 now abandoned, entitled IMPROVED METHOD FOR CONSTRUCTION OF SLAB-FACED PANELS.

The US. Pat. of Kastenbein, No. 2,855,653 shows a system for casting tile-faced panels which includes sucking the individual tiles against a resilient mat to produce simulated concave joints between adjacent tiles. The casting box described in Kastenbein is custom built for this particular purpose and, in order to allow use of high vacuum, is quite massive and expensive in construction.

Experimentation has demonstrated that it is impossible to vacuum seat even a small array of face-down brick, brick slabs, slate, glazed tile or glazed brick that are just resting on even the softest of a sponge rubber surfaced vacuum pad. One cannot get staisfactor'y' uniform vacuum sealing of commercially obtainable brick faces or brick slab'faces without a relatively heavy pressure being exerted on the backs of such individual facings, up to 2 pounds per square inch. When one realizes that full solid brick (3% inches) only weigh about 0.28 pound'per square inch and inch thick brick slabs only weigh 0.067 pound per square inch, the inadequacy of eachbric k or slabs own weight is readily apparent. A 32. square foot panel would have about 210 normal (2% X 8 inches) brick slabs, any one of which if it is not sealed against the vacuum pad can prevent attainment of proper vacuum sealing on ther rest. It is most common to experience no less that 15 percent socalled leaky (unseated) slabs when said slabs, just resting on a vacuum pad, have normal texturing and/or sand finishes thereon. Manual seating of slabs which fail to seat is impractical; can you imagine 15 men each trying to locate two unseated slabs that he could get his hands on and exert up to 32 pounds down-pressure on, at exactly the same time his 14 helpmates were doing the same with their 28 hands. This is no exaggeration, the present inventor has personally repeatedly failed to attain a vacuum seal with both of his hands pushing down on a slab when a test panel being set up only had a total of facing slabs.

It is speculated that Kastenbein, of Tile Council of America, got by without seaters because he was primarily dealing with 4 X 4 inches quarry or bathroom tile, glazed in most cases, made under very controlled factory conditions where high quality control standards exist and where each and'every tile is individually inspected for warpage before being packaged.

SUMMARY OF THE INVENTION There is provided in accordance with the present invention a casting box having at least one vacuum line connection through its floor with a laminated insert plate which includes a resilient upper layer provided with one vacuum line opening for each slab, and which incorporates conduits extending from the openings to communication. with the casting box floor. A placement grid having individual cells for receiving individual slabs is received inthe casting box on the insert plate upper layer. After a slab has been placed in each cell a heavy seater is lowered onto the slabs to force them into sealing contact with the insert plate resilient upper layer and a vacuum is drawn through the casting box floor to hold the slabs so tightly against the insert plate resilient upper layer that the layer bulges up between adjacent slabs. The seater is removed; then the placement grid is withdrawn with the assistance of removable lateral shims and a settable composition such as concrete is poured into the casting box upon the slabs. The panels so formed have slabs set therein with simulated semi-flush concave joints. A modified device for production of panels faced with slabs on both sides is also disclosed.

The teaching of the present invention makes possible the rapid and reversible conversion of present day unfaced casting beds and forms to faced casting beds and forms with practically complete utilization of all corn- 1 ponents of the former and without in any way damaging said components or preventing their rapid change back totheir original use. The vacuum plate inserts of the invention have such very limited unsupported spans that have to resist the forces generated by relatively high vacuum that relatively inexpensive three-eighths inch plywood can be utilized as core plates, those having more than the needed strength required to prevent any undesirable flexure. Regardless of whether the vacuum bed covers one square foot or two hundred square feet, the areas unsupported by sponge rubber sheet on either side of the vacuum plate inserts stay the same for any given facing material and are always minimal.

What must be done to a conventional precast concrete panel form to change from the manufacture of ordinary unfaced concrete panels to slab faced panels in accordance with the invention is to pad up the sides of the present casting boxes by an amount equal to the compressed thickness of the vacuum plate insert, normally about 1 inch, and drill and tap the needed vac uum inlets in the base plates. The l-inch thick shim strips can be inexpensively made of either wood or metal. Both vacuum plate inserts and shim strips need but minimal storage space when not in use, being storable on ends and edges, respectively. The tapped vacuum holes are easily and quickly plugged with cap screws of the right length. In addition, using the vacuum system would require auxiliary equipment consisting of a suitable vacuum pump with a largeaccumulator, piping, valving, placement grid, or grids, and a seater, or seaters as described more fully hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings FIG. 1 is a schematic view of exemplary apparatus for carrying out the panel casting invention,

FIG. 2 is a top plan view of the casting box showing (proceeding leftwardly) successive stages in the casting of a brick slab-faced panel,

FIG. 3 is a longitudinal sectional view line 3-3 of FIG. 2,

FIG. 4 is a vertical sectional view of an enlarged scale detail of the casting box showing the cap screw pressing against the grid which rests on the vacuum plate insert,

FIG. 5 is a vertical sectional view of an enlarged scale detail of the casting box showing one right angle spacing washer fitted on the placement grid,

FIG. 6 is a vertical sectional view of the base plate of taken along a modified, deep seater for seating brickslabs against the vacuum plate insert prior to pouring of the settable backing,

FIG. 7 is a vertical sectional view of a portion of a panel constructed in accordance with the principles of the invention and especially illustrating the concave joint simulations formed between adjacent slabs,

FIG. 8 is an end elevation view of a modified casting box for production of panels faced with slabs on both sides, and

FIG. 9 is a vertical sectional view of a portion of a panel constructed in accordance with the principles of the invention using the apparatus of FIG. 8.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS In the following description, to be read in conjunction with the drawings, reference is made to a particular example, used for illustration. Of necessity, the example includes brick slab sizes, joint simulation thicknesses and the like. Obviously the system may be used to manufacture panels of different sizes, thicknesses, joint types and sizes, using different slab material or sizes than those depicted and described, while making full use of the principles of the invention. Brick slabs is used herein to denote face brick, tile, thin brick, e.g., l-inch thick, cut slate, and similar wall construction materials.

Referring to FIG. 1, a panel casting system 10 is shown including a casting box 12, which receives a vacuum plate insert 14, upon which brick slabs B are placed face down using a removable placement grid 16 to achieve conformity to the desired array pattern. The slabs are sealed against the vacuum plate insert with the aid of a heavy seater 18, a vacuum is drawn through the vacuum plate insert 14 to maintain the slabs sealed against the insert and to elastically distend the insert so that it bulges up between adjacent slabs. Concrete or other settable backing C is then poured into the box over the slabs, screeded off and allowed to set. The panel P, when removed from the box includes a face F of brick slabs B provided with a simulation of semiflush concave joints J between adjacent courses of slabs and between adjacent slabs in the same course.

Assume that a is-inch jointed, running bond J is desired and that the brick will average 8 inches in length and 2%. inches in face height.

Further assume that the desired panel P is to be independent and approximately 8 feet 6 inches in height and 10 feet 0 inch in width, X (2% inches 54; inch) Xi-inch determines that our panels would be 102 54 inches, or 39 courses high, (39 (2% inches inch) 56 inch) and 117 inches or 14 brick wide, (14 (8 inches inch) inch).

An independent panel is one that is complete by itself, one that does not have to carry on" joint work that was started in a previous panel, or one that is initiating joint work that its adjoining panel is to carry on with. An independent panel using %-inch joints is three-eighths inch higher and three-eighths inch wider than a carry on panel and three-eighths inch wider than a starter panel as its brickwork is completely surrounded by %-inch joints, not just on one side or just on either the top or bottom, but on both.

The form cavity" in the casting box 12 for this panel will be the exact required dimensions, namely, 102 ")4 inches by l 17 -56 inches. Assume that these panels P are to be made in a precast plant which has casting table 22 (casting box floor), some feet in length, 10 feet wide, equipped with steam coils, hydraulic tipping divices and vibrator hangers its entire length, and that it is serviced by several 20-ton overhead cranes. Further assume that the production schedule calls for the production of four panels per day. Four sets of casting box sides 24 of the required height to match the thickness of the desired panel P plus the depth taken up by the vacuum pad insert 14 would be set up to contain the 102 inches X 117 )5 inches outside dimension of the brick faced panel P.

The vacuum pad insert 14 basically includes a flat 56-inch, ,z-inch, or 96-inch steel plate, or is-inch, 76-inch, 96-inch or 54-inch sheet of plywood 26 cut to an exact 102 inches X 117 "96 inches, minus 1/32 inch all around. Each half and each full brick slab B to be used on the bottom face P of these panels P is laid out on this insert 26 and on the geometric center of each is drilled a 7/ l 6-inch hole 28 through the sheet 26, (one' that could be tapped out to one-half inch for fill in purposes later on if required, or for the insertion of lifting eyebolts).

Around the bottom edge of this vacum plate insert is glued 2 inches wide X %-inch thick strips 30 of medium sponge rubber. Also on roughly 5 X 4 inch centers, 4 by 3 inch pads 32 of the same sponge rubber are glued but not to cover the vacuum access holes 28.

To the top side of the vacuum plate sheet 26 is glued a complete covering 34 of 36-inch closed cell sponge rubber sheeting which has previously had slot cutouts 36 made in it to match the 7/ 16-inch holes provided in the steel plate or plywood sheet 26. These cutouts are approximatelyfi X 5 inches for each full brick and are set on the geometric centers of where these are to be located, and X 2 inches for each half or header brick, also on the geometric centers of where these are to be located.

The casting table bottom plate 22 is drilled and tapped at 38 for several vacuum lines 40, all of which spread out from a single fast action control valve 42.

The vacuum plate insert 14 with its sponge rubber borders 30, pads 32 and covering 34 is lowered into the form cavity 20 where it seats itself on the casting table bed plate 22.

The vacuum plate insert 14 is not only one of the key to system l0s success, but it makes vacuum gripping practical for the first time. As conceived and practiced, vacuum can be applied to an unlimited area without creating even a semblance of warpage or strain on the containing surfaces. The bottom rubber backing strips 30 and pads 32 absorb the forces which might otherwise be spent in warping or buckling any or all containing surfaces.

The vacuum plate insert 14, because it is an independent unit, and a relatively cheap one, that can be fabricated in just a few hours, is one key to a versatility that can be extremely beneficial. Such vacuum plate inserts 14 can be used with practically any and all of the conventional casting beds 12 now in existence, which means that established panel producers can change over to the system 10 at avery minimum of expense.

In essence, the vacuum plate insert is a replaceable combined gasket and manifold which seals between the casting table and the brick while communicating vacuum from a few locations in the casting table, to the lower face of each to pull each brick so tightly against the insert that (a): the inserts upper spongy layer bulges up in a bevel between adjacent brick and prevents panel backing composition from running under the brick to spoil what will become the panel face F.

The remainder of the vacuum generating system shown in FIG. 1 is madeup of standard elements which are believed adequately explained by captions in the figure. The system benefits from the use of a relatively large accumulator 44, so one can use a reasonably siz ed vacuum pump 46. The accumulator allows one to exhaust all the lines and the open areas of the vacuum plate inserts almost instantaneously without but a very small and easily acceptable loss in the degree of vacuum held as a minimum. While the system 10 has an overall seater 18 weight of 35 pounds per brick equivalent, certain rough faced slabs may require up to 55 pounds in order to effect a perfectly tight seal with the insert face 34. Thirty inches of vacuum will produce the equivalent of about 60 pounds per 2 541 X 8 inches brick face, but for acceptably reliable commercial production it takes the combination of the seater 18 weight and the initial vacuum grab through the insert 14 to attain the needed gasketing of the brick to the insert.

The step following installation of the insert 14 in the casting box 12 is installation of the placement grid 16, which is lowered down onto the top of the sponge rubber top covering 34 and which contains positive locating edges for all the full and half slabs B needed to face the panel P. This grid is preferably constructed so that all of its locating surfaces are to the left and to the bottom. The grid 16 itself preferably offers a reasonable clearance for each brick to be inserted in its cells 48. Thus, if the grid is made of A X 56inch horizontal and A: X 34 inch vertical" cold finished bars, the space available to insert 2 k X 8 inches brick slabs is 2 X 8 A inches which covers very wide size variations among the individual brick.

Laborers next fill all the grid cells 48 with brick B and while doing so shove each slab to the left as far as it can go and downward toward the bottom grid member in the same manner.

The grid 16 should be about one-fourth inch less in height than the thickness of the slabs B to be used. Thus, a grid for l-inch thick slabs should be threefourths inch in height. Slabs should stick up above grid one-fourth inch, so that a sponge rubber lined, flatbottomed seater 18 can effectively contact the backs of the slabs and yet miss the top of the slab locating grid 16. The 4i-inch differential connot be increased very much without the possibility of ending up with the grid being locked in place by slab edges, that, due to slab deformities or tilt, just slightly overhang the ribs of the grid. It would, for instance, probably be impossible, a significant percentage of the time, to remove a 34-inch high grid inwse with 3 i4 inches high full size brick even with the float" provision later described herein.

Regular .vertical grid ribs 50 should not exceed rs-inch material unless very, very uniform sized slabs are going to always be available. By using iii-inch material, the length of the grid void spaces will be onefourth inch greater than the nominal length of the slabs, (%-inch joint assumedand 8 inches long brick inch A: inch), which makes possible the use of considerably over-length slabs as well as providing extra removal clearance. v

One-fourth inch stock can be generally used for horizontal grid ribs'52 for brick slab heights rarely vary even one-sixteenth inch over average size. A 55-inch, (its 5 1 inch assuming the use of a 36-inch joint), normal clearance rarely causes either slab placement or grid removal problems.

Regardless of the differential in height of the ribs of the locating grid and the thickness of brick or slabs being used, it is always desirable and often necessary to provide a releasing mechanism for the placement grids, after a vacuum seal has been attained on the brick or slab faces, if one is to easily and freely lift out said placement grids as is necessary prior to pouring the panel. When the bottom surface of the seater contacts the exposed back surface of each and every brick or slab and then transmits to each brick or slab some two pounds plus per square inch of downward pressure, (as the seater assembly comes to rest), the faces of the slabs or brick are forced downward, not only insuring a sealing contact with the top soft rubber lining of the vacuum plate insert, but also in an unescapable percentage of the brick involved, creating substantial contact between either or both of the brick or slabs vertical edges that were initially, (at the time of placement), in just very light contact or just adjacent to vertical edges of a placement jig. Since all brick or slabs are initially positioned in the oversize jig openings in a common manner, generally to the left and downward, rather substantial pressures can be built up in those directions with the resulting locking in of said placement grids against the adjacent two sides of the casting box. The subsequent application of vacuum generally takes over this created friction and maintains same as long as the vacuum is left on.

Removable iii-inch flat metal spacers do provide a means of freeing grids from the two-way build up of side pressures by releasing the grids and allowing them to be lifted out without difficulty. Such fiat spacers, however, can present their own removal problems. If these flat spacers do not protrude up and above the sides of the molds a sufficient distance to allow them to be firmly grasped by hand or with pliers or other suitable tools, they, themselves, can be extremely difficult to remove. if they do extend up above the casting box sides for easy insertion and removal, then they can be easily hit by and badly damaged by the heavy seaters as they are swung into place and lowered down into the casting box. One-eighth inch flat steel strips cannot stand up to a swinging mass weighing up to five tons or better. Thus, the alternate use of screws to make possible an easy and positive way to exactly locate and then later release placement grids is the preferred means.

On those two sides of the casting box, corresponding to the two directions in which the brick or brick slabs are placed in contact with the edges of the placement jigs cavities, one provides, at properly spaced intervals, tapped-holes at an elevation-equal to the midpoint of the placement grids frame members. lnto these tapped holes are inserted cap screws of such a length that their heads seat after the opposite ends protrude an exact one-eighth-inch. This procedure eliminates any damage being caused to the placement jig by overtightening of the'spacer screws and make their thread-in practically foolproof for even the most inexperienced workman. A further safeguard can be incorporated which insures that the cap screws can. only be withdrawn the exact amount needed to leave their ends flush with the interior sides of the casting box.

If all slab placements are to be made to the left of respective grid cells, then with a is-inch joint being sought, one can use is-inch outside vertical edge ribs 54. However, to avoid possible lock-ins, it is much preferred to use Ai-inch stock in conjunction with easily installed or removed /s-inch spacers 56 (FIG. 2). The use of such spacers permits one to attain the equivalent of zero installed clearance between the sides of the jigs (placement grids) and the sides" of the casting form, thereby insuring correct and thus reproducible slab placement as well as providing a means of attaining some side to side and top to bottom float" after the slabs have been gripped, by removing the spacers.

Again assuming that is-inch joints are called for, then one using spacers, would need -inch spacers 56 to space out the placement grid from the bottom vertical side of the casting form if the recommended 54-inch material was used, (541 96 inch it; inch). The use of the %-inCh spacer here provides the means of obtaining top to bottom float once the slabs have been seated and vacuumlocked in place.

This float is achieved by use of left vertical and bottom horizontal ribs with spacers 56, and is one of the real keys to most successful use of the locating grids. Preferably the spacers 56 are in the form of short L- shaped channels removably received in slots 57 formed in the top and exterior of the left-most and bottom outside grid elements. The float one obtains in both directions not only makes it possible to lift out the grid prior to pouring, but to do it easily, even in spite of the tilt and slab deformity problems that generally exist.

If it is not already apparent to those reading this specification, it should be pointed out that vertical, horizontal," top and bottom are sometimes used herein to denote orientations which would be correct for the casting system only if it were tilted up to match the orientation of the panel P when the panel becomes aprt of a wall. Actually, of course, the casting is usually carried out horizontally. Thus the terms are used in the sense of convention, and not necessarily in the sense of actual spatial orientation.

The flush concave joint J that is obtainable with the system 10, is of course a result of the high vacuum employed creating sufficient pull to displace a sufficient amount of the vacuum plate insert sponge rubber facing 34 and causing same to bulge into the void joint areas to give a concave outline the the same.

The typical slab placement grid 16 which provides two like edge contacts for each and every slab B is the ultimate. Any laborer, who places slabs in such a grid, does not have to waste any time or effort or exercise any special skill or judgement to properly adjust the spacing or alignment of any slab. All anyone has to do is place successive slabs in empty grid cells and to move each slab as far as possible to the left and keep same down adjacent to and-in'contact with the horizontal ribs. With this type of positioning grid one can easily set and position slabs even while blindfolded.

There are, of course, much simpler slab locating grids. The simplest grid has no intermediate vertical ribs. This grid would offer an edge locating surface for the lefthand starting brick in each course, but the balance of the brick in each course would have to be spaced apart by eye. The chances are that one would most always find it necessary to make time-consuming lateral adjustments as each course has been filled with slabs, so as to better even up the width of the void vertical joint spaces. Grids have been made where the two outside brick of groups of three have positive locating ribs or pins which positively locate them, leaving only each center brick to be centered in the void space by eye. This system is quite effective when the slabs rest on or are only slightly embedded in fresh mortar. Under such conditions the slabs themselves are floatable" in that they offer but very slight resistance to the very slight displacement that may be necessary to free a lock-in of the grid. When the vacuum gripping system 10 is used, the slabs are just about unmovable, and grid lock-ins" can be real serious. If there are any projections of slab edges over both left and right vertical ribs, then the grid just cannot be lifted out. Any built-in float produced by the use of spacers, or other means, is simply ineffective in such a situation. Removable float producing spacers 56 can only be effective when slab contact with vertical ribs is either always to the left, (or to the right, if the spacers are positioned to the right), and when slab contact with the horizontal ribs is always at the bottom, (or to the top if the spacers are positioned at the top). Float can only be effectively achieved when slabs and spacers are so located that the removal of the spacers automatically makes it possible to shift the grid horizontally and vertically so that it at once loses contact with the slabs and is therefore verti cally removable with ease.

Slab locating grids can also be more economically constructed if simple short pins are substituted for complete vertical ribs 50. It is a relatively simple task to gang drill and then machine tap required holes for such locating pins which are threaded on one end.

Slab locating grids per se have been used for many years for slab placement purposes by others. The use of spacers, whether they be actual shims that are inserted between the sides of the panel form and the slab locating grid or threaded bolts 56' (FIG. 4) that are screwed in threaded openings 58 the appropriate form sides to produce and maintain desired clearances, is believed to be an innovation. Up until the advent of the vacuum gripping system 10 for slab position retention, the need for float creation could not have been fully appreciated.

The next operation following placement of the brick slabs in the grid cells 48 is to lower down onto the backs of all the brick B in the individual cells 48 the seater 18 having a flat pad 60 that is just a bit smaller than the panel to be poured and having a semi-soft rubber facing 62 and having a fairly equally distributed weight equivalent of about 25 pounds per full brick in the panel. It has been found that even soft sponge rubber if used for the inserts or face 34 offers enough deformation resistance to prevent the gross weight of a rough faced brick or brick slab from making a usable seal, that is, make enoughof a seal with the vacuumplate insert 14 to permit a vacuum to be readily achieved.

When relatively thin brick slabs are to be used as facing material, it is necessary that the seater 18 have on its base side protruding and spaced pads 60, each faced with suitable sponge rubber facings 62'. These pads should be at least one-half inch smaller both ways than the slabs they will contact and preferably about as thick as the grid is high. This is necessary so that the seater can contact each and every slab even though that slab actually is only as little as one-third in thickness, the depth of the grid opening.

The seater i8 is preferably a heavy, cast, cranemovable body as depicted in FIG. 1,- but the pad 60 and Once the seater has weighed upon the slabs, the vacuum valve. 42 is opened, and the slabs B are literally grabbedby-the vacuum. j

When panels are being faced with very thin and thereforequite fragile brick slabs and/or very rough faced slabs, someminor problems-may be experienced with vacuum leaks. By arranging the vacuum plate inserts'support layer of. sponge rubber, so as todivide up the panels exterior face into severalmore or; less equal divisions areawise, and by separately piping gauged vacuum lines with individual valves to each such division, one can easily and quickly pinpoint where a broken or impossibly rough faced slab or slabs are located. The faultless sections can be held onvacuum while the troublesome area is shut off,the seater raised out of the way, the faulty slabs replaced, the seater returned and the vacuum again turned on. The seater 18 is then raised and carried over to thefnext panel (if an assent bly line operation is being employed) or'put in storage. The incipient panel is next checked for brick alignment, the grid 16 removed, and the panel backing then laid veneer walls." A few such panels are .laid up by 7 her or metal templates with the void joint spaces then tem not only furnished excellent and perfectly clean exbeing filled with a very fluidgro'ut.

Several years ago a" Texan tried to promote a vertical poured vacuum held single brick width panel. Thatsys- 7 posed jointwo'rk, but also included the ability to incorera, for obvious reasons, would like to see whole full r size brick-incorporated inso-called brick faced panels 1 in:preference to thin brickslabs, even though the latter .porate both vertical and horizontal steel reinforcing, a very valuable option. Howeventhe costliness of the casting forms and other economic factors doomed the efforts to commercialize that system.

Both the European and American brick manufactur- I obviously offer some cost savings. Eventually the cost poured, screeded and'finished;" l he backing may be any conventional settableconstruction materialfsuch as cementor a synthetic plastic substitute.

Because'of the simplicity of changing vacuum plate inserts, grids, and seaters, the system l0lends itself to rapid production changes, and if the runs are long enough, then the labor savings involved willeasily pay for extra expense involved with the necessary tooling up. I 1 I I The joint work with the system 10 is superb, and the panel faces come out beautifully clean and unmarked, as there is no leakage.

While the seater may be the simplestunit in the system 10 of panel making, it is nonethelessimportant. Without a seater it is doubtful one could ever get a 4 X 8 feet, or larger, panel's compliment of slabs sufficiently in contact 'withthe foam rubber surface of a vacuum plate insert to create a vacuum seal excepting when uniformly smooth, probably glazed, slabs are used. A seater 18 actually takes the place of hundreds of non-existent hands without which the system 10- would be impracticable for use with most slabs.

A- typical closed cell sponge rubber to use for the sponge rubber layers of the vacuum plate insert and the seater is manufactured by Rubatex.

Although it is intended that-the casting box be used horizontally, it may be tipped toan upright condition during the panelmanufacturing process, for instance to facilitate removal of the completed, hardened panel.

it should be apparent-that, priorto hardening of the.

- factor-will likely cause most faced precast panels to utilize' brick slabs, for concrete per cubic foot will always be substantially lower in {cost thanan equivalent amount of brick. However, there may be, for some time at least, a substantial market for single width (3 la- 4 inches) brick panels if only because of the promotional effort that may be putforth-bybrick manufacturers the world over.

There are two ve "serious andmajor drawbacks to most of the economically producible single width brick panels that have been or are in production today. In the first place, not one of such top. poured panel's being made today has a quality of workmanship on exposed brick faces that would be acceptable to most buyers in this country. The second important fault of practical contemporary single width brick panels is that not one of them can be economically reinforced with both horizontal and vertical reinforcing steel. Any single width. brick wall that is held together with ordinary mortar,

that has to be transported from plant to job site, that has to be hoisted into place,-and that finally has to be capable by itself of withstanding hurricane force winds,

must be reinforced'with'steel. In addition, a reinforced single brick width wall at once changes cla'ssification from non load bearing" to load bearing. When insulation is not important, this load bearing feature can be very important. A reinforced 3 %-inch brick panel can under-many such conditions replace an 8 inch wall. Three and three-fourth-inch-thick reinforced brick mately horizontal and vertical ties.

. I The jsystern fdisclosedin thisldwl l cht is susceptible of modifications to make possiblethe economical pre panel backing composition, the upper (rear) surface of the panelmaybedecoratedby partly embedding decorative'material'such as marble chips, brick slabs or the like in the. setting backing composition. Furthermore,

' extensivelyusedin European basically just'a single steel rods must be] positioned in'roughly thecenter of, the panel thickness "and, of course,ibe completely emcasting of reinforced sin'gle',.width brick panels, panels Q that also have top qualityenposed jointwork. These are slight andvery inexpensive modifications.

To. most effectively reinforce'any masonry panel, the

" bedded in'the mortarusejd.'To get such rods in the cenbrick width wall, the equivalent to our present hand} ter of a single width brick panehone must use 'sof called cored brick, pre e ablynstant hole type for 8 inch long brick and five iholesfor ll li-inchlong brick. The round core holes such brick are about-l in diameter and always have one such void at the midpoint in each brick horizontally and vertically. The l-inch diameter of such core holes insures both the easy threading" of A-inch round steel through multiple courses top to bottom of a panel and the total encasement of the steel in mortar of more than sufficient thickness around same.

With normal %-inch mortar joints, such as would be used on most panels, the use of 56-inch horizontal and vertical reinforcing steel can present some real problems. The average Vs-inch total clearance" can give some placement and positioning troubles unless the coursing is nearly perfect, the brick used on size and straight edged. Most any system with extra time, care, and top notch supervision can cope with the above, but the real sticker to date has been how to top pour reinforced single width brick panels, having %-inch joints, using I s-inch round steel and ending up with full joints and with full utilization of the steel used. It is difficult enough to top pour single width brick panels without the most substantial blockage that %ll1Ch round steel, positioned half-way down the joint cavity offers. Even without reinforcing steel to contend with, the mortar used must be almost like thin soup, the brick used must be pre-soaked to use up their powers of absorption, lest they prematurely dry up and thus stiffen any mortar that comes in contact with them before it has time to settle down into and fill the multiple 3 l-inch narrow and deep voids that joint areas consist of. Even if intense vibration is added to the above tricks-of-the-trade antidotes, one could too often end up with serious unsightly void spaces that should have been full of mortar as well as with steel that is not able to do its job because it is only partially surrounded with mortar.

The modified casting equipment for producing reinforced panels is identical to that for the system as depicted with the exception of the bottom or top casting box side wall, which would, at appropriate points along its length, have is-inch holes drilled and be supplied with suitable flush plugs to fill said holes when they are not being used. The A-inch round vertical reinforcing rods would be passed through these holes when being inserted into their respective vertical row of the bricks center core holes. These holes would be drilled on the center line of the vertical reinforcing rods location and have their centers three-sixteenths inch above the centers of the brick core holes the rods are to be enclosed in. The flush plugs will always be in place except when the rods are being inserted. All sides for this type of panel casting box would, of course, be just high enough to allow the fresh concrete to be leveled over the top of the single brick, on edge and with the vacuum seal in effect. The casting box includes a level surface, the bottom of which would be piped at several locations to a common manifold the manifold would be capped on one end and fitted with a suitable valve at the other end this valve in turn would be piped to a suitable large vacuum accumulator tank which in turn would be piped to a vacuum pump of suitable capacity. Four side forms of sufficient length would be fastened to the base plate so that their interiors would enclose the exact area of the desired panel to be cast. The bottom or top side form would be suitably drilled and furnished with flush plugs for the insertion of the vertical reinforcing steel in between first and second pours. A suitable vacuum plate insert would be placed in the casting area.

The ctual casting procedure would follow very closely that employed in system 10. Assuming that the casting box sides have been fastened down, (clamped or bolted), oiled, and the proper vacuum plate insert has been lowered in place; the following steps are carried out in order:

1. Set brick face placement grid in position and install release shims or run in release screws.

2. Properly fill grid with full and half brick face down. These bricks inmost cases will have to be pre-soaked in water to nullify their normal absorption capabilities.

3. Bring up the seater and lower same onto the backs of the bricks and slack off thus creating a seal.

4. Open the vacuum line valve.

5. Remove the seater.

6. Remove the shims or withdraw the release screws and remove the locating grid.

7. Make partial pour of very thin mortar, preferably, in most cases, with vibrators attached to side plates turned on, up to a level approximately three-eighths inch below the top of the brick core holes.

8. Remove plugs, one at a time, in side adjacent to panel bottom, (or top for that matter), and thread into the opposite alternating core holes and vertical joint spaces one-fourth inch, (or other suitable sized), round reinforcing rods which had been pre-cut to exact desired length.

9. Install sufficient hangers to hold these vertical reinforcing rods so that their tops are generally even in height with the midpoints of the bricks core holes. The reinforcing rods at this stage would be submerged in the mortar approximately one-eighth inch of mortar being over the tops of the rods.

10. If specifications call for wire tying of the horizontal and vertical rods together, one must at this time drape each vertical rod at the point same is going to be crossed by a horizontal reinforcing rod, (where a wire tie is specified). Draping simply consists of hooking a preformed wire tie down under the vertical rods, bringing the looped ends up and bending each one over the corners of its brick on opposite sides of the joint void into which the horizontal reinforcing rod will be inserted.

11. Install pre-cut to length horizontal reinforcing rods by dropping same in their respective horizontal joint cavities, and, if necessary, pushing them down in the mortar until they contact and rest on the tops of the previously installed vertical rods.

12. If wire ties were called for and draped prior to placing the horizontal wires, then they would be twisted up tight at this time with a regular wire twisting tool.

13. Balance of the pour would next be carried out, and the top exposed surface brushed or screeded as called for.

14. As soon as the mortar has set up sufficiently the sides can be removed, the vacuum shut off and released.

Referring now to FIGS. 8 and 9 of the drawings, a variation of the casting box is shown for use in fabricating panels faced with slabs on both sides. For equivalent parts, numerals as used in connection with parts described'in connection with FIGS. 1-7 are used.

To explain most succinctly, the system 10' uses two casting boxes 12 hinged together at one edge. Each of these is provided with a vacuum plate insert 14 and a placement grid 16 and releasing means exactly as explained in connection with FIGS. 1-7; brick slabs are placed in all of the placement grid cells of both casting boxes, seated using two seaters 18 (or the same seater 18, successively) and a vacuum drawn through the casting boxes to maintain the brick slabs gasketed against respective vacuum plate inserts and the inserts uppermost resilient covering 34 bulged up between adjacent slabs on each vacuum plate insert; the seaters are removed; the placement grids are released and removed, only then does a significant divergence in method occur. The two casting boxes are folded up to verticality i.e., until their formerly upper edges engage all the way around and lock together. Then a fluid, hardenable composition is poured into the mold so created and allowed to harden. The vacuum is then released and the mold opened to provide a two-faced panel with semi-flush concave joint simulations as shown in FIG. 9.

Since the casting boxes 12, vacuum plate inserts, placement grids and seaters used in the FIG. 8 embodiment do not materially differ from those fully explained aboveand shown, e.g., in FIGS. 1-6 except as explained briefly above and in more detail hereinafter the matters which would only be redundant if re-explained and re-depicted will not be.

Alternate system 10 is a combination top and vertical pour set-up that utilizes the best of both basic methods. System 10 is an answer to the demanding need of a method that will permit facing of both sides of individual panels with the ease, quality of jointwork and clean faces that can be achieved with system 10 for single faced panels, (vacuum gripping and top pour).

Basically the equipment needed to use this alternate system 10' is a pair of horizontal, opposed and hinged precast panel forms 12 that are fitted with suitable vacuum plate inserts 14, along with matching slab placement grids 16 with releasing shims or screws, an appropriate seater l8, and a vacuum pump (FIG. 1) 46 with a large accumulator 44. The three containing sides 24 of each casting form would generally be ofa height that would equal the thickness of the vacuum plate insert l4 when under vacuum, plus one half the desired thickness of the panel to be poured. Thus, if the vacuum plate insert 14 under vacuum is 1 inch thick and the panel is to be 8 inches thick, then the form sides 24 should be 5 inches high. Two such panel forms when faced with brick, placed under vacuum and as described in relation to FIGS. 16 tilted about the hinges 66 into vertical, wall-edge to wall-edge contact and in perfect alignment as shown in full lines in FIG. 8 to create a combined vertical pour form. Once this assembly has been properly clamped or bolted together, e.g., utilizing the clamps 68, it can be very easily filled with fluid mortar through open top 70 to form a panel that is faced on both sides with any desired material (FlG. 9),one that has superb exposed joint work and one whose faces generally come free from the casting forms 12 clean as a whistle. Further, by having the base channels 24, when being tilted into pouring position, come to rest on a suitable heavy base beam 72, which in turn is resting on a suitable gang roller 74, one provides the means to move a curing panel axially along the track plate 76 to one side long before it could be safely picked up, thus making the casting forms available for reuse much, much sooner than they would normally be available possibly doubling or even tripling their productive capacity. This alternate set-up can thus provide the means for most economically producing two faced panels using slabs of just about any thickness that have very wide size variations, almost the greatest of face deformities, in any desired pattern or bonding and with the most popular flush concave joints. In combination with fast setting mortars, this alternate can at least double output per square foot of building space consumed from that achievable with other systems. Labor reaches a high level of utilization because all the advantages of cleaning, set up, slab placing, etc., is done on the ground" in a horizontal position while the pouring is done in vertical position with its sizable reduction in exposed surface.

Assuming that the previously poured panel has reached a curing stage that would permit removal of the hinged base plates,

1. Remove cap screws from exposed backs of base plates that hold 5-inch side and bottom channels in place.

2. Remove master clamps that have held the opposing form assemblies tightly in contact with each other.

3. Lower sides, which have vacuum plate inserts thereon, to a horizontal position.

' 4. Clean off vacuum plate inserts and areas surrounding same to which the channels 24 are bolted.

5. Bolt down another set of bottom and side channels 24 and oil their faces.

6. Place slab placement grids in position and place spacers in position. i

7. Properly fill grids with face down slabs.

8. Bring seater over and down onto backs of slabs.

9. Turn on vacuum to each side 12 as it is ready.

10. Remove seater and then the grid.

ll. Remove base bolts that fastened adjacent side channels together, (which surround previously poured panel).

12. Remove these side channels.

13. Slide this still curing panel to one side out of the way thus also towing into position an attached alternate base support channel 72 on its own rolls 74.

14. Tip up the hinged forms into contact with each other and bolt adjacent vertical side channels to each other.

15. Place main holding clamps in position and tighten same.

16. Pour mortar through open mold top and screed.

17. At proper time lift up and carry previously poured panel to storage thus freeing the base channels on which this panel was resting as well as the base support channel and its rolls for reuse.

It should now be apparent that the method and apparatus for casting slab-faced panels as described hereinabove possesses each of the attributes set forth in the specification under the heading Summary of the Invention hereinbefore. Because the method and apparatus for casting slab-faced panels of the invention can be modified to some extent without departing from the principles of the invention as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications as are within the spirit and scope of the following claims.

What is claimed is:

1. Apparatus for manufacturing slab-faced panels having semi-flush concave joints simulations of exposed, hardened backing composition between adjacent slabs, comprising:

a casting box having a floor and peripheral sidewalls;

means defining at least one vacuum inlet through said casting box floor; vacuum plate insert removably introducible into the casting box for covering the floor thereof; said vacuum plate insert having a lower facing of resilient gasketing material and an upper facing of resilient gasketing material with an intermediate layer of rigid material separating the upper and lower gasketing materials and conduit means defined in the vacuum plate insert communicating the lower facing thereof coincident with the location of said casting box floor vacuum inlet with a plurality of slab-receiving sites arranged in an array on the upper facing of the vacuum plate insert;

a placement grid having means defining a plurality of slab-receiving cells arranged in an array, said grid being removably receivable in the casting box upon the vacuum plate insert so that each cell of the placement grid encompasses a slab-receiving site on the vacuum plate insert;

a seater adapted to simultaneously apply a downward force upon all of the slabs when the slabs have been received in all of the cells for seating all of the slabs against the resilient gasketing material of the upper facing of the vacuum plate insert.

2. The apparatus of claim 1 wherein said seater is a sufficiently heavy body to exert a downward force of at least 25 pounds per 2 /4 X 8-inch brick equivalent upon each slab when resting upon all of the slabs, said seater having resilient facing means on the underside thereof where it contacts each slab.

3. The apparatus of claim 1 wherein said casting box and said placement grid are rectangular, wherein said placement grid is of slightly smaller horizontal dimensions than said casting box; and removable shimming means for shimming said placement grid against two adjacent sides of said casting box, so that, following placement and seating of the slabs the shimming means may be removed and the placement grid shifted slightly laterally to facilitate removal thereof from the casting box.

4. The apparatus of claim 3 wherein each shimming means comprises a threaded bolt threadably received in one side of one of said casting box and placement grid and arranged to bear against one side of the other of said casting box and placement grid.

5. The apparatus of claim 3 wherein each shimming means comprises an L-shaped clip having a vertical leg inserted between one side of the casting box and one side of the placement grid and having a horizontal leg supported upon said one side of the placement grid.

6. The apparatus of claim 1 wherein the facings of resilient gasketing material are composed of closed cell sponge rubber.

7. Apparatus for manufacturing slab-faced panels having semi-flush concave joint simulations of exposed, hardened backing composition between adjacent slabs on both faces of each panel, comprising:

two casting boxes, each casting box having a floor and at least three adjacent peripheral sidewalls;

means defining at least one vacuum inlet through each casting box floor;

two vacuum plate inserts, each vacuum plate insert removably introducible into a respective said casting box for covering the floor thereof; each vacuum plate insert having a lower facing of resilient gasketing material and an upper facing of resilient gasketing material and conduit means defined in each vacuum plate insert communicating the lower facing thereof coincident with the location of the respective casting box floor vacuum inlet with a plurality of slab-receiving sites arranged in an array on the upper facing of the respective vacuum plate insert;

at least one placement grid having means defining a plurality of slab-receiving cells arranged in an array, said at least one grid being removably receivable in the casting boxes upon the vacuum plate insert therein so that each cell of the placement grid encompasses a slab-receiving site on the respective vacuum plate insert; and

means hinging the two casting boxes along one peripheral sidewall of each for swinging movement of the two casting boxes into a vertical position wherein the formerly upper edges of the at least three peripheral sidewalls of the two casting boxes respectively engage one another to define a mold cavity between them.

8. The apparatus of claim 1 further including:

a seater adapted to simultaneously apply a downward force upon all of the slabs in at least one said casting box when the slabs have been received in all of the cells therein for seating all of the slabs against the resilient gasketing material of the upper facing of the vacuum plate insert in said at least one said casting box.

9. The apparatus of claim 7 further comprising:

a track plate, roller means received on said track plate, a base support channel mounted on said roller means and adapted to receive and support the two casting boxes as the two casting boxes are swung to verticality and engagement.

10. The apparatus of claim 9 further comprising:

means removably clamping respective sidewalls of the two casting boxes to one another; and wherein said hinging means comprises two frame means each underlying one said casting box when the casting boxes are in a horizontal condition; said frame means then lying adjacent one another on opposite sides of said track plate and said roller means; axle means on one side of each frame means extending parallelto said track plate; and bearings supporting each axle means for rotation about the longitudinal axis thereof to bring both said frame means to a vertical condition on opposite sides of said track plate and said roller means.

* 18 III t UNITED STATES PATENT OFFECE m QER'HFEQATE @F QORREC'NQN Patent No. 3,75 Dated ugilst 7, 19??) PAUL S. KELSEY Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the-heading of the patent, line [75], after The Susquehanna Corporation, Alexandria, Va.

insert assignee for the territory of New England Signed and sealed this 15th day of January l97 L.

(SEAL) Attest:

EDWARD MQFLETCHERJR. Attesting Officer RENE D. TEGTMEYER 7 Acting Commissioner of Patents FORM P0 1050 (10-69) USCOMM oc 60376 was i U 5,6OVIRNN1NI HHNHm. OHIH I569 O--.\u6-.l.H

Claims

1. Apparatus for manufacturing slab-faced panels having semiflush concave joints simulations of exposed, hardened backing composition between adjacent slabs, comprising: a casting box having a floor and peripheral sidewalls; means defining at least one vacuum inlet through said casting box floor; a vacuum plate insert removably introducible into the casting box for covering the floor thereof; said vacuum plate insert having a lower facing of resilient gasketing material and an upper facing of resilient gasketing Material with an intermediate layer of rigid material separating the upper and lower gasketing materials and conduit means defined in the vacuum plate insert communicating the lower facing thereof coincident with the location of said casting box floor vacuum inlet with a plurality of slab-receiving sites arranged in an array on the upper facing of the vacuum plate insert; a placement grid having means defining a plurality of slabreceiving cells arranged in an array, said grid being removably receivable in the casting box upon the vacuum plate insert so that each cell of the placement grid encompasses a slabreceiving site on the vacuum plate insert; a seater adapted to simultaneously apply a downward force upon all of the slabs when the slabs have been received in all of the cells for seating all of the slabs against the resilient gasketing material of the upper facing of the vacuum plate insert.

2. The apparatus of claim 1 wherein said seater is a sufficiently heavy body to exert a downward force of at least 25 pounds per 2 1/4 X 8-inch brick equivalent upon each slab when resting upon all of the slabs, said seater having resilient facing means on the underside thereof where it contacts each slab.

7. Apparatus for manufacturing slab-faced panels having semi-flush concave joint simulations of exposed, hardened backing composition between adjacent slabs on both faces of each panel, comprising: two casting boxes, each casting box having a floor and at least three adjacent peripheral sidewalls; means defining at least one vacuum inlet through each casting box floor; two vacuum plate inserts, each vacuum plate insert removably introducible into a respective said casting box for covering the floor thereof; each vacuum plate insert having a lower facing of resilient gasketing material and an upper facing of resilient gasketing material and conduit means defined in each vacuum plate insert communicating the lower facing thereof coincident with the location of the respective casting box floor vacuum inlet with a plurality of slab-receiving sites arranged in an array on the upper facing of the respective vacuum plate insert; at least one placement grid having means defining a plurality of slab-receiving cells arranged in an array, said at least one grid being removably receivable in the casting boxes upon the vacuum plate insert therein so that each cell of the placement grid encompasses a slab-receiving site on the respective vacuum plate insert; and means hinging the two casting boxes along one peripheral sidewall of each for swinging movement of the two casting boxes into a vertical position wherein the formerly upper edges of the at least three peripheral sidewalls of the two casting boxes respectively engage one another to define a mold cavity between them.

8. The apparatus of claim 1 further Including: a seater adapted to simultaneously apply a down-ward force upon all of the slabs in at least one said casting box when the slabs have been received in all of the cells therein for seating all of the slabs against the resilient gasketing material of the upper facing of the vacuum plate insert in said at least one said casting box.

9. The apparatus of claim 7 further comprising: a track plate, roller means received on said track plate, a base support channel mounted on said roller means and adapted to receive and support the two casting boxes as the two casting boxes are swung to verticality and engagement.

10. The apparatus of claim 9 further comprising: means removably clamping respective sidewalls of the two casting boxes to one another; and wherein said hinging means comprises two frame means each underlying one said casting box when the casting boxes are in a horizontal condition; said frame means then lying adjacent one another on opposite sides of said track plate and said roller means; axle means on one side of each frame means extending parallel to said track plate; and bearings supporting each axle means for rotation about the longitudinal axis thereof to bring both said frame means to a vertical condition on opposite sides of said track plate and said roller means.