US1900301A - Concrete floor joist form construction - Google Patents

Description

March 7, 1933. H. READ CONCRETE FLOOR JOIST FORM CONSTRUCTION Filed July 29. 1929 I Bnnentor N Q g Ie/zr Read l Mattel-nag.

1 0 NW X. K E 7 NY m 3 m. \N\\ N w H UM LN--- \\\QW\ QWQN NW QNN 2Q .BQWN KT 7 1% 4 w mx Patented Mar. 7, 1933 UNITED, STATES I HENRY READ, or TULSA, OKLAHOMA concnn'rn rLoon JOIST ronm c'onsrrnucrron Application filedJul y 29,

This invention "relates to concreteyjoistformwork construction, and more especially to a construction of the character named for cooperative relationship with floor slab form work.

In a p-rior'invention I provided a floor slab formwork construction which could be readily sprung or bowed downward to withdraw r it from its support so that it could be used for another floor before the concrete upon it of Figure 1.

was sufficiently cured to carry a load, the ad vantage'of such type of floor slab formwork permitting a contractor to lay the floors of a building with fewer floor slab forms than is necessary where the formwork must; remain in position for each floor, until theconcrete is fully cured. v I

My particular object in this invention is to make a similar provision for the joistf0rm-. work so that the latter can be removed at the same time that the fioorslah-form'work is removed and used for another floor before the c'oncreteof the 'fioor from which they-are withdrawn is 'fullyfcu-redlf Anotherjobject isto provide a construction which simplifies and 'cheapens the work of laying concrete floors and at the same'time facilitates the progress of such work..- v

With the above and other objects in view as hereinafter ap pe'ar,'theinvention consists incertain novel and useful features offconstruction and combinations of parts as hereinafter described and claimed;'and in order that it maybe fully understood, reference'is to be had to th-eaccompanying drawing, in which: 7 Figure 1 is a fragmentary perspective view showing a joist formwork for concrete joist construction, embodying the invention, the

drawing also disclosing floor slab forms preferably used in "conjunction with 'the joist formwork, and other complemental features, Figure2 is a section takenon the line II II Figure 3 is a section III-III' of Figure 1. v

Figure 4 is an enlarged fragmentary perspective view showing one of the brackets which carry the sides of thejoist "form as a unit, oneof the spreadersorcrossbars for taken on the line 1929f Serial No. 33;}715.

bracing the adjacent joist forms in fixed -rela-' tion and for supporting the flooring forms between the joist forms, andone of the locks for holding the spreaders in interlocked relationship with the bracket. f V I Referringto the drawing in detail, 1 indicates a, pair of channel iron or equivalent beams of a building, and 2'stringers secured 1n any suitable manner to said beams. The beams may be any suitable distance apart. If spaced a substantial distance apart, for

example/16 feet apart, it is desirable to pror vide an intermediate support centrally between the beams. As shown in Figure 1 said support is in the form of a horizontal 4X4 or equivalent member extending parallel with'the beams, andis arranged with itsupper face in the plane of the upper edges of the stringers 2. Each 4X4 will rest'upon a suitable number of vertical shorers 5,0'ne only being' sho wn. The shore'rs as customary are provided with' scabs 6, andoverlying the latter and fitting against opposite sides of each shorer is a pair of stringers 7 which parallel the member 3 and are flush withthe upper 7 face of the same. Wedges 8 or any other suitable "means are interposed between the scabs and the stringers to insure that the upper edges of the latter are at the proper height which, as-stated, is in the plane of so the upper side or face of'the member 3.

In a construction where the intermediate support construction described is employed, it will be preferable to aline joist forms, the same resting at their adjacent ends on the stringers 7 and at their opposite other ends on the respective stringers Q of the beams 1.

This arrangement leaves a gap between the adjacent ends of the sides 9 of the joist forms, and'means are provided to close said gaps, vas hereinafter described.

' The sides of each'joist form, which prefer ably converge downward slightly, are fastened together as'a unit by oppositelyfacing angle brackets 10,the upper arms of the angle brackets being secured respectivelyto the outer" faces of the sides of the joist forms, and the other arms extending horizontally below said joist forms sides and standing in overlapped relationship, suitable means such' as bolts and nails being employed to adjustably secure the overlapping portions of the brackets together, the adjustment being necessary so that the sides can be disposed. at distances apart to correspond with the width of the concrete joist to be provided between them. There will be a bracket construction such as described near each end of each pair of sides, and any desired number of extra or intermediate brackets of the same" type necessary to insure rigidity of the joist forms and proper support of floor slab forms, hereinafter identified, Figure 1 showing two oi? such intermediate bracket constructions.

The upstanding arms of the brackets are of channel form, with the channel faces juxtaposed to the respective sides 9, and at their upper ends the upright portions are notched to provide upwardly-facing shoulders-11.

To constitute braces between the adjacent joist forms, cross bars or spreaders 12 are employed, each spreader resting on the shoulders 11, of opposite brackets, and having arms or tongues 13, projecting between the' upper ends'of-the brackets and the joist sides 9 to which such brackets are secured. The spreaders 11 thus serve to not only brace adjacent joist forms against approaching movement butalso serve to prevent them from spreading apart. The spreaders are preferably of channel construction. .7 To guard against accidental disengagement of a spreader from its engaged brackets, a pairof similar channel locking devices 14, are-employed. These devices are provided with short longitudinal slots 15, terminating at their outer ends in. oiisetting slots 16, the latter converging downward slightly'with respect to the ends ofthe locking devices abutting the spreaders to hold them in the notches of the brackets. The slots of the locking devices pivotally and slidingly engage nails, screws or the like 17 driven into the adjacent sides of the joist forms. When a locking device is to be disengaged from a; spreader, it is tapped "upward lightlyat its pivoted end so that, because of the inclination of the ottsetting portion of the slot, it shall move endwise to withdraw slightly from the engaged spreader. If this does not result in the looking device swinging downward to inoperative position, force can be applied to slide it slightly with the pivot engaging the portion 15'of the slot. When it is moved enough, the locking device will be free to swing down to a pendant or inoperative position." The re- Verse manipulation of the locking device is followed in disposing it in operativeposition with relation to the spreader. The joist forms are provided with soiiits 18, which rest upon the brackets uniting the sides of such forms. Where the beams are spaced apart sufficiently to require the intermediate supporting member 3 and stringers 7, so that a' gap or space is left between alined joist short sofiits 19 which rest squarely, upon the member 3 and the stringers 7, and cannot be removed after the concrete material is applied, until the shorers and the said stringers 7 and member 3 are taken down, which is not until the concrete is thoroughly set and the whole floor work is self-supporting.

Any suitable floor form or floor forms may be employed. In the construction shown two floor forms are arranged in longitudinal alinement between the beams 1. They each consist of a sheet meta'l top plate 20 secured to underlying spaced strips 21 extending parallel with the joist forms and therefore transversely with respect to the beams. The two floor forms preferably terminate at their ends over the stringers 2 and .7 thus leaving an uncovered joint between them like that between the adjacent ends of alined joist forms. These spaces must be'covered, and to accomplish this metal saddles 22 of 111V6It8Cl'U-f01111 are fitted down upon the adjacent ends of alined floor forms and oist forms, as shown clearly in Figures 1 and 2, the arms 23 thus closing the spaces between the engagedjoist form sides and, by engagement with the latter, are prevented from endwise slippage. The spaces at the opposite ends of and below the floor forms, viz., where thelatter are contiguousto the beams 1, may be closed in any suitable manner, as by fillingstrips 24 upon the underlying stringersjQ, one filler strip being shown in Figure 1.

Withthe 'parts arranged'as explained it will be apparent that the concrete material in plastic form, can be deposited or poured so as to fill the beams if of the U-type' shown, and also fill the joist forms and spread over the floor forms and thesaddles to the required depth. I. a

When the concrete has set for a sufficient length of time, to be self-supporting for short spans when bearingno load, the locking devices can be loosened and the spreaderstremoved. This permits the floor vforms to be bowed down and lowered from position, the forms bowing'downwardsufficiently, as indicated by the dotted line in Figure 2, to permit them to clear the upper edges of the underlying arms of the brackets of adjacent joist forms. If it is desired then to remove the joist forms, the wedges are loosened and the stringers 7,-usually nailed in a few; places for safety,are pried off. The joist sides and the main soflits 18, and the'saddles can then be taken down, leaving the short soifits 19 i removal of the joist forms, as units, is made easy by tapering the end extremities upward slightly, as, if the ends were vertical, some care would have to be exercised to hold them against tilting in order to pass them downward readily betweenthe member 3 and the beams 1. It is also desirable that the sides of the joist forms shall converge downwardly, as shown, to facilitate their withdrawal, with the main soffits, from the-partly cured concrete joists without chipping the latter.

From the foregoing it will be apparent that where the span between beams is twice or a greater multiple of the length of the floor forms and joist forms, which are preferably about 8 feet long, it is necessary to use an intermediate support or supports, and the support or supports, represented here by the shorers, member 3 and the short soflits, remain in place until the concrete is completely cured. It has been found however that there is no necessity for leaving the stringers and floor and joist forms and saddles in place for more than one-fourth of the full curing period. Because of this fact it is'possible, when pouring not more than one floor a week, to employ only one set of the parts last named for the entire building, whereas the equipment of shorers, member 3 and the short sofiits must be in full for each floor of the building, until the concrete is fully cured, .a

period of from fourteen to twenty-one days.

It will be apparent from the drawing and description that I have produced a construction which is susceptible of modification in various details within the principle of construction and mode of operation involved, and therefore within the spirit and scope of the appended claims.

I claim: g

'1. Spaced supports, a joist formwork resting at its ends on said supports and consist ing of parallel sides, angle brackets secured to and underlying the sides and secured together in pairs, the arms of the brackets engaging the sides, having portions spaced from the latter and also having upwardly-facing shoulders, a horizontal spreader resting at one end on each shoulder and provided with a laterally-projecting tongue fitting in the said space between the respective formwork side and bracket, a locking device fitting against the joist side and endwise against the sideof the corresponding spreader to hold the latter on the shoulder of the bracket and the tongue in the said space, and provided with a longitudinal slot terminating at its end remote from the spreader in an extension disposed in downwardly-converging relation to the engaged side of the spreader, and a pin pivotally and slidably engaged by the slot andv secured to the adjacent joist formwork.

2. In a concrete floor joist form construction, spaced supports, hollow'joist forms resting at'their ends on adjacent supports, op-

posite-upright arms secured to the near sides of adjacent joist forms and terminating short of the upper edges of said sides, a horizontal spreader between and disposed below the plane of the upper edges of said forms and resting upon the said arms and also engaged with said arms to prevent relative spreading movement thereof, and means pivotally and longitudinally movably mounted on said forms for engagement withand disengagement from the spreader to hold the latter against accidental disengagement by sidewise movement, from the said arms.

3. In a concrete floor joist form construction, spaced'supports, hollow oist forms resting at their ends on adjacent supports, opposite-upright arms secured to the near sides of adjacent joist forms and terminating short of the upperedges of said sides, a horizontal spreader between and disposed below the plane of the upper edges of said forms and resting upon the said arms and also engaged with said arms to prevent relative spreading movement thereof, means pivotally and longitudinally movably mounted on said sides for engagement with and disengagement from the spreader to hold the latter against accidental disengagement by sidewise movement, from the'said arms, and a floor slab form fitting snugly between adjacent joist forms and resting directly upon said spreader. i

In testimony whereof I aflix my signature.

' HENRY READ.

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