US1327081A - False work for concrete floors - Google Patents

Description

'8.1. BRANSON AND E. C. STRATHMANN.

EAEsE WORK Foa CONCRETE ELooRs.

APPLICATIQNFILED AUG. I8, 1916. RENEWED OCT. 27, 19H9. LSQLUL Patented Jan. 6, 1920.

2 SHEETS-SHEEI I.

S. J. BRANSON AND E. C. STRATHMANN.

FALSE WORK FOB CONCRETE FLOORS.

APPLICATION FILED AUG. 18. 1916. HENEWED OCT. 27j, 1919.

Patented Jan. 6, 1920.

2 SHEETS-SHEET 2.

ATTORNEY UNITED STATES PATENT OFFICE.

SAMUEL J. IBRANSON, OF CHICAGO, ILLINOIS, AND EDWARD C. STRATI-IMANN, OF INDIANAPOLIS, INDIANA, ASSIGNORS TO THE CONCRETE FORMS COMPANY, OF INDIANAPOLIS, INDIANA, A CORPORATION OF INDIANA.

FALSE WORK FOR CONCRETE FLOORS.

Application filed August 18, 1916, Serial No. 115,594. Renewed October 27, 1919.

To all whom t may concern:

Be it known that we, SAMUEL J. BnANsoN and EDWARD C. STRATHMANN, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, and at Indianapolis, in the county of Marion and State of Indiana, respectively, have invented a new and useful False Work for Concrete Floors, of which the following is a speciiication.

It is the object of our invention to provide a falsework structure for use in the construction of concrete Hoor slabs,v which falsework shall be inexpensive, can be ut up and removed with a minimum of laior, can be reused as often as desired, is automatically given the proper spacing when set up, and eliminates the use of expensive fillers of clay tile, steel tile, or gypsum blocks which are used between joists in other methods of construction.

This present application has certain features in common with our co-pending application Ser. No. 125,352, filed October 13, 1916. The broader claims covering the subject-matter common to the two applications are tion.

The accompanying drawings illustrate our invention. Figure 1 is a sectional view through a section of falsework embodying our invention, being taken substantially on the line l1 of Fi 2; Fig. 2 is a section on the line 2-e2 of Fig. 1; Fig. 3 is a section taken in substantially the same plane as Fig. 2, but showing on a smaller scale a larger section of the falsework, including two gird` ers; F ig. 4: is Ia section on the lines lt of Figs. 1 and 2; Fig. 5 is a section showing how shallower j'oists may be used with the same falsework units; and Fig. 6 is a section on the line 6 6 of Fig. 5.

In the construction of concrete floors in buildings, there is usually a flat floor slab 10 which is crossed on its under side by parallel joists 11 extending in one direction, which joists rest on a smaller number of parallel beams or girders 12 or masonry walls extending in a direction transverse to the joists, the girders being heavier than the joists, and usually being constructed either of steel .ll-beams which may or may not be embedded in concrete or of concrete with embedded reinforcing steel rods 13, and'ftthe Specification of Letters Patent.

presented in said co-pending applica-- structed of ordinary Patented Jan. 6, 1920.

Serial No. 333,687.

joists being of concrete and usually integral with the floor slab. The joists are also usually provided with suitable reinforcing rods lat; and frequently the girders are provided wit an enlarged upper portion so as to produce a T-shape cross section.

Heretofore, in constructing floors of this character, parallel rows of tile have been used to fill the downwardly opening grooves between adjacent joists, these tiles sometimes being left in place and sometimes being removed. These tiles have in most cases been of terra cotta, though in recent constructions instal tile and plaster blocks have been used to some extent. In either case, the tile has ordinarily been supported on a complete false floor, and something in addition to the tile has always been used to furnish the forms for the under faces of' the joists. Moreover, skilled labor has usually been required for placing the tiles, which constitute the forms for the bottom 0f the floor slab and the sides of the joists, for the tiles must be placed in parallel rows With considerable accuracy.

IVe do away with the necessity for this false `floor, and for the necessity or" the great care in the placing of tiles in rows on such false Hoor. To this end we provide centering units 20, long enough or nearly long enough to reach from one girder to another, and provide the lower edges of these units with outwardly projectinglanges 21 which abut against the flanges of the adjacent units to provide the proper spacing ofthe units and to furnish the forms for the under faces of the joists 11. These units may be made of various materials, such as steel plates, or boards covered with sheet metal; but where long life is not and low i'st cost is essential, they are most conveniently conwooden boards, dipped in creosote. Each centerin unit comprises a top 22, two sides 23, and the flanges 21. The top 22 furnishes the form for the under face of the slab 10, and the sides 23 furnish the forms for the side faces of the joists 11. The sides- 23 are preferably collapsible toward each other, to permit the removal of the unit from the finished. floor. This collapsibility is conveniently obtained by hinges 24, which are provided in the top 22 of each unit, extending parallel to the edges and near one edge, so that the side 23 and til ange 2l at that edge of the top' 22 may be swung to the dotted line position (Fig. 1) to permit the unit to be withdrawn rom the downwardly opening groove in the under face of the floor. The wider part of the top 22 and the adjacent side 23 are preferably interconnected by triangular braces 25, to hold them in proper relative position.

In order to provide for adjustments in the length of the centering units U-shaped metal channels 30 are provided at the ends thereof, each such metal channel conforming to the upper and outer surfaces of the unit 20, so as to fit closely against the upper surface of the top 22, the outer surfaces of the sides 23, and the upper surfaces of the flanges 21. The flanges 31 of the channels, which anges lie upon the' flanges 21 of the centering units, abut against the corresponding, flanges 3l of the channels 30 of the adjacent units, as clear from Fig. 1. rlhese metal channels are made of rather thin-gage sheet metal, and may be slid lengthwise of the units 20 so that they are either completely thereon as shown in Fig. 3 or project beyond the ends thereof, as shown in Fig. 2, the projecting ends of the channels in the latter case resting on the forms for the girders 12. The projecting ends of the channels 30 are closed, so as to providel the forms for the T-heads of the girders at the ends of the downwardly opening grooves in the under face of the floor.

In order to support the centering units in place, any desired number of transverse supporting planks 40, set on edge and eX- tending parallel to the girders 12, may be used. Sometimes two such transverse planks 40 are sufficient, one at each end; but usually it is preferable also to have one or more intermediate ones, such as one in the middle of the lengths of centering units, as clear from Fig. 3. These transverse planks 40 are supported on posts 4l, held in any suitable manner. The posts for the transverse planks 40 at the ends of the centering units may also serve as supports for the girder forms 42, as shown in Fig. 3; though this is not necessary, and the ends of the centering units may be supported independently of the girder forms, as shown in Fig. 2. The centering units 20 are sufficiently rigid so that between the planks 40 they are selfsupporting and capable of carrying the superposed load of the concrete ofthe floor slab and joists, without any additional support.

Fach transverse plank preferably has fastened thereto a series of uprights 45 the centers of which are spaced apart by distances equal to the distances between the centers of adjacent joists 11. rlhese uprights 45- are of proper size to fit loosely into the centering units 20; and they space these units apart, and correctly and easily determine the positioning thereof, because each centering unit fits over at least two upri hts 45 on the two or more transverse plan (s 40 on which it rests. In vorder to hold the centering units firmly after they have been put over the uprights 45, and yet to permit easy removal, wedges 46 are provided for Wedging them on such uprights.

When it is desired to make joists of less depth than provided by the centering units, a board 47 the joist-groove formed by the sides 23 and flanges 21 of adjacent centering'units, this board being supported at the desired height, if necessary, by cross-cleats 48 resting on the flanges 2l, as shown in Figs. 5 and 6. By providing cleats 48 of different thickness, any desired depth of joist may be thus obtained.

We claim as our invention:

l. A falsework for concrete floor construction, comprising a plurality of centering units each of which is of inverted U- shape in cross-section and at its lower edge has an outwardly projecting flange of sutlicient width `to reach the adjacent centering unitA so that the two centering units cornprise a form for the floor slab and the sides and the undei' face of a concrete joist, each centering unit being formed of hinged parts movable to bring its vertical sides closer together to facilitate removal.

2. A falsework for concrete floor construction, comprising a plurality of centering units 4each of which is of inverted U- shape in cross-section and at its lower edge has an outwardly projecting flange of sutlicient width to reach the adjacent centering unit so that the two centering units com--` prise a form for the Hoor slab and the sides and the under face of a concretejoist, the top ofk each centering unit being provided with va longitudinal hinge joint nearer one edge than .the other whereby the unit may be collapsed to bring its vertical sides closer together to facilitate removal.

3. A falsework for concrete floor construction, comprising a plurality of centering--units each of which is of inverted U- shape in cross-section and at its lower ed e has an outwardly projecting flange of sugicient width to reach the adjacent centering unit so that the two centering units comprise a form for the floor slab and the sides and the under face of a concrete joist, the top of each centering unit being provided with a longitudinal hinge joint whereby the unit may be collapsed to bring its vertical sides closer together to facilitate removal.

4. A falsework for concrete floor slab constructions of the joist type, comprising a plurality of spaced supports, a lurality of combined beam and form mem ers resting on said supports and spanning the spaces of proper width may be laid in Learner between them, each of said members comprising a longitudinal upright portion and a longitudinal horizontal portion having .support upon said upright portion and projecting laterally from the lower edge thereof, both portions spanning spaces between said supports to constitute forms for the joists, and said members being alternately oppositely placed and mating in pairs at the projecting edges of said horizontal portions, the pairs of such members being spaced apart, and a plurality of top pieces coperating with the upper edges of and having support upon the upright portions ot' adjacent members of adjacent pairs and closing the space between such pairs toconstitute Jforms for the under surface of the slab, the spaced supports being spaced apart by distances materially greater than the height of said upright portions so that they are suiiiciently far apart so that said members act as beams as well as forms, and said members being sutiiciently rigid as beams to carry the'load of the superposed concrete, each top piece being permanently connected to the adjacent beam and form members, and being provided with a hinge permitting said adjacentbeam and form members to be swung toward each other.

5. A falseworlr for concrete construction, comprising a plurality of spaced supports, a plurality of members resting on and eX- tending transversely to said supports, said members being L-shaped in cross section and alternately oppositely placed and mating in pairs at the projecting edges of the lisorizontal portions of said l..shaped memers, the pairs ot l -shaped members being spaced apart, a plurality of top pieces cooperating with the upper edges of the uprights of the adjacent E -shaped members of adjacent pairs and closing the space between such pairs, the l.shaped members being sutliciently rigid so that they are selfsupporting between said supports and will carry the superposed concrete, and parts rigid with spaced supports and properly positioning and spacing the pairs ofl Lrshaped members, said top pieces being permanently connected to the adjacent l.- shaped members to form units, and said units being provided with hinges permitting the L-shaped members thereof to be swung toward each other to facilitate removal from the concrete.

6. A system of falseworlr for concrete construction, comprising spaced supports, members set on said supports and disposed to act as joists over a clear span, said members being spaced in a series of substantially parallel pairs with each pair of members kacting as side molds for a concrete joist, the

two members of a rable, tween and at the lower edges of the edgewise members of the several pairs and respectively rigidly attached to said two edgewise members to support the concrete of said concrete joist, and top members coperating with the upper edges of said edgewise members and illing the space between pairs, each top member being permanently connected to the two adjacent edgewise members to form a unit, and said units being provided with hinges to permit said edgewise members to be swung toward each pair being readily sepa- .other to facilitate removal from the concrete.

In witness whereof, we have hereunto set our hands at Indianapolis, Indiana, this 15th day of AugustfA. D. one thousand nine hundred and sixteen.

SAMUEL J. BRANSON.. EDWARD C. STRATHMANN.

two laterally projecting members be-

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