US2687193A - Metal falsework carrier for reinforced brickwork and reinforced concrete structures - Google Patents

Description

Aug. 24, 1954' HlNzE METAL FALSEWORK CARRIER FOR REINFORCED BRICKWORK AND REINFORCED CONCRETE STRUCTURES Filed Aug. 18. 1950 2 Sheets-Sheet 1 t f Fiel 1 Z (Z l 1 INVENTOR Oitol'linge ATTORNEY Aug. 24, 1954 o. HINZE 2,687,193

METAL FALSE'WORK CARRIER FOR REINFORCED BRICKWORK AND REINFORCED CONCRETE STRUCTURES Filed Aug. 18, 1950 2 Sheets-Sheet z INVENTOR 0H0 Hinge ATTORNEY Patented Aug. 24, 1954 UNITED STATES PATENT OFFICE METAL FALSEWORK CARRIER FOR REIN- FORCED BRICKWORK AND REINFORCED CONCRETE STRAUCTURES Otto Hinze, Hannover-Kleefeld, Germany, as-

signor to Johann Friedrich Zwicky, Zurich,

Switzerland Application August lS, 1950, Serial No. 180,186

8 Claims.

Floors sand-roofs; asvwell as other. structural:

parts .of dwelling houses and industrial buildings are nowfrequently built 'up of prefabricated concrete' units. This system aiiords the following advantages:

Thaprefabricated units canbe prepared indoorsindependentlyoi the exterior weather conditions. Fewer. skilled workers are necessary hesion, resistant to. bending. and shear, that.

characterizes monolithic-cast concrete. The clamping fixation otherwise preferentially employed has .to be dispensed with. In consequence,

prefabricatedunits are less suitable foubuildings of appreciableheight, such asmulti-story houses.

Moreover, the great .weight ofthe prefabricated. units for conveying, lifting andshifting calls forcorrespondingly, powerful lifting and conveying tackle. Furthermore, a structure built up of prefabricated. units must be so designed thatsubsequent supplementary, loads. are excluded. Caulking work may, not be performed. And pipework can be subsequently secured only. by straps.

or pipe clipsplaced round stanchions and. girders. It isaccordinglynot alwayspossibleto dispense with monolithic buildingmethods in the case. of floorsin structures subjected to. heavy stresses, as for instancein multisstory dwelling houses, factorybays, and buildings which are constantly exposed to considerable vibration from machines.

Ceilings, roofs andvaults of brick, reinforced brickwork or reinforced concrete areproduced monolithically by means of negative moulds, known as'shuttering; casingqfalsework or centering. Th'ese'mouldsneedremain in position only'for. a relatively short time, and they are therefore not expected to exhibit'verylong life. The casing or falsework. is generally made of timber. with" its" concrete side left rough, more orless carefully finished, oreven lined with sheet steel. The boards or panels are placed on squared'timbers which are arranged with a spacing of-"70 to 80 cm. between each two and supported' -by bearers consisting ofsquared timber. The bearers are carried by vertical props, usually round timbers, which are set up on planks and wedges at intervals of 0.80 to 1.10 metres according to the anticipated loading. With an eyeto"buckling. resistance, close spacing of the slender stanchions subjected to compressive stress is absolutely necessary. The props are, moreover, strengthened horizontally and vertically by poling boards or battens, for horizontal stresses may arise even when, according to plan, only vertical loading was anticipated. Conventional timbered floor or ceiling falsework structures have therefore a veritable maze of vertical supporting members. No work can be successfully performed in a room in which such falsework is erected; it is even diificult to pick ones way through the resultant confusion of prop and poling boards. According to the type of cement used andto the greater or lesser stressing the time which must elapse before the falseworkis removed may range from 2 to 21 days, and the so-called emergency props remain in positionl l days longer. The obstructive effect ofwooden falsework is therefore a substantial drawback. Furthermore, the high consumption of timber is at present no longer justifiable from the point of View of nationaleconomy. Finally, timber falsework calls for a comparatively heavy expenditure of working time for fitting and removal.

Eiiorts have long been made, therefore, to replace timber fioor-ialsework by metal ialsework.

Thus, for instance, trussed beams and trussirames have been designed which are assembled from a. plurality of separate units. These supporting systems have a considerable structural height, their component units are relatively heavy and unwieldly and in consequence inconvenient.

For these reasons it can doubtless be claimed that even today timber falsework is still preferred.

A low structural height is not suitable in the case of the falsework carrier hitherto known built up of a plurality of component elements, as it leads to sagging as a result of the absence of vertical props. Needless to say, the ceiling would likewise sag if cast on such a sagging falsework; the sag would be aggravated by the elTect of the superload. For this reason, falsework carriers have hitherto been made very high. The result of this has been comparatively heavy structural elements which, when assembled, are obstructive.

The object of the invention is to provide camberable metal falsework carriers built up of light and convenient structural elements which are easily assembled and dismantled, camberable to olfsetthe sagging that is inevitable under load, and in addition have suiiiciently lateral rigidity to absorb any horizontal stresses that may arise sive than that'ofthe timber falsework hitherto usual, and they are adapted to give the ceiling as smooth as possible an undersurface.

According to the invention this problem is solved by short, low and light-weight carrier elements or sections butt-j ointed at the top member and connected at the bottom member by coupling nuts, said carrier sections taking the form of a parallel trussed frame and being arranged for assembly into homogeneously-acting, space-spanning metal falsework carriers or girders.

The several sections of carrier are advantageously made of such length that they can be fitted into a standard system of dimension units. In this way, for instance, using only carrier sections in the serial lengths of 0.625 in, 0.9375 m. and 1.25 In. all spans of 1.25 m. upwards dimensioned in accordance with the standard dimension unit of can be spanned. Or by means of serial lengths of 0.50, 0.60 and 0.70 metres, all spans of 1 metre upwards, rising by intervals of 0.10 metre, could be accommodated.

The carrier sections designed in the form of.

a parallel trussed frame enable material to be economized and a structure of the lowest possible weight to be achieved.

The drawing shows by way of illustration satisfactory examples of the construction of falsework carriers in accordance with the invention. In said drawing,

Fig. 1 shows an elevation of an erected falsework carrier consisting of two lateral and two central truss elements, with the ceiling produced with its aid in section;

Fig. 2 shows in transverse section erected falsework carriers in the form of the so-called band falsework for ribbed ceilings made from reinforced stone or reinforced concrete;

Fig. 3 shows schematically in elevation a falsework carrier consisting of two truss elements;

Fig. 4 is an enlarged end View;

Fig. 5 is a front view of an element of the falsework carrier;

Fig. 6 shows a cross-section through an element of a construction slightly differing from Figs. 4 and 5 Fig. '7 is a front view of an element arranged at a side wall;

Fig. 8 is a side view of the lateral suspension support of a truss element according to Fig. 7;

Fig. 9 is a side view of the upper chord member or beam of the truss element and a turn buckle linking two elements together in end-toend relationship at their lower chord member or beam, and being always adjustable and linked to the elements at both sides and separately;

Fig. 10 is a plan view of the turnbuckle according to Fig. 9; while Fig. 11 shows the eye screws of the turnbuckle according to Fig. 10.

As will be seen from Figs. 1, 4, 5, '7, 8 and 9, the metal falsework carrier of the present invention freely spans the space to be bridged, and is camberable and detachable as is evident from Figs. 1 and 9. It consists of at least two structural elements or trusses, each consisting of at least an upper chord or beam 3 (Fig. 4) a lower chord 4 and the rods 5, two neighboring elements I and 2, 2 and 2, and 2 and I being in end-to-end relationship in the line of th upper chord 3. The elements are safeguarded against shifting in relation to each other in the plane of abutment (Fig. 9) and in the line of their lower chords 4 by means of connecting elements which are il- I lustrated in the embodiment of the invention shown as being in the form of turnbuckles 8 (Figs. 9 to 11) which are adjustable lengthwise and are linked to elements I, 2, or 2 and 2, or 2 and l, to one side and separately It is immaterial whether a wall-adjacent or anchoring element I links up with a central element 2, as in Fig. l; or whether, according to such figure, an intermediate element 2 links up with a second intermediate element 2; or an intermediate element 2 links up with a wall-adjacent element I; or a wall-adjacent anchoring element links up with a number of intermediate elements as in Fig. 3.

The upper chords 3 are made from U-shaped profile sheet metal; this may be replaced by any other suitable, preferably commercial profiles (for small spans and loads also light profiles). The lower chords 4 preferably consist of round steel rods or tubes. It is possible to use also builtup sections as shown in Fig. 6. The upper and lower chords ar connected by one or two series of round steel rods or pipes 5, preferably welded to the chords I and forming the struts of the latticework; the illustrated connection may be replaced by any other suitable latticework or paneling between the upper and the lower chords as conditions may require, and even a continuous web. The upper chords are so shaped at their ends that they may be abutted flatly along a wide area; in addition, they can be held together at their abutting faces by means of screw bolts or by slip-on locks or clamps 9, as shown for instance in Fig. 9.

The locking devices for the upper chord 3, such as screw bolts or slip-on locks or clamps, are particularly suitable for the mounting of the falsework carrier, as they prevent th elements from gapping. At the same time, the linking of the upper chords serves to take up any transverse and horizontal stresses which may occur in the course of the construction of ceilings. In order to make possible an easy removal of the falsework, the locking devices of the upper chord are advantageously arranged in such a manner that after the setting of the ceiling they are not exposed to any stresses worth mentioning.

With the help of the turnbuckles, the falsework carrier is aligned in the line of the lower chords I, and the desired arching is gauged. When removing the falsework, the turnbuckles serve as releasing devices; the falsework carrier, being under tension, is easily detached.

The permanent structural parts for the support of the ceiling are used as the hangers for the falsework carriers, as shown in Figs. 1 and 3. For this purpose the wall-adjacent supporting elements I are provided with tongue-like projections I8 which are rigidly connected with such parts. Figs. 7 and 8 show such an end piece with tongue I8 in front and side views. Movable supports or brackets fixed to the wall may also be used to support the falsework carriers. Struts I! which are wide in relation to their height can be provided to inter-connect several adjoining falsework carriers and thus increase their lateral rigidity. Fig. 2 shows at I5 the arrangement of transverse rods for increasing the lateral rigidity of the entire unit consisting of a number of falsework carriers; in their stead. or in addition, diagonal rods may be provided, which may connect for instance the first false meswwea worki carrierzelementitoztherlefthvithrtheslastrelee ment :to 7 th'ecright:

Falsewor-k carriers Ema'de: in? accordance with: thel particular advantage-1 Off. highiload capacity: combined. with'light weight and reasy hand ling; Thus with :a \falseworki car rier according to th invention: for 'use in thebuilding of apartments; a weight 'ofsilzlskgz/meter at :laniassumed spantlof =6 meterssleadss to a ibende ingcmoment such! that :thei weights l of i the *cone creteuusually used: form the: construction' of ceil-" ings as well as of the traflic and of the receptacles inventions havec" with the prethe fact that through the elimination of stiffen-- ing supports. the possibility of. their sinkingl. on undependabl floors is avoided, as well as premature and undesired stress on the ceilings below. An almost unlimited life of the falsework is ensured as against the use of timber which is perishable and may easily be stolen, by the possibility of using high-grade materials in the construction of the falsework, by safeguarding against rust, by doing away with loose parts and thus making loss thereof impossible, and by the practically non-existing wear and tear. In so far as metal falsework carriers have already been proposed, they have, owing to their telescopic structure, to their construction of varying static systems on the pattern of bridges, or through their remaining in the building structure as reinforcements, a much greater weight, and are unwieldy, mostly non-camberable or capable of being arched, and for these and other reasons have not been introduced to any considerable extent in the practical building technique.

I claim:

1. A light-weight structurally self-contained sectional lattice beam structure, suited to engage supports at its ends and to be loaded between said supports, comprising: a top member composed of at least two sections which abut end to end in their load bearing position to react horizontally against one another directly in thrust; releasable means joining adjacent sections of the top member; a bottom member composed of a like number of sections which are aligned and react in tension, said top and bottom members being of substantially the same length; means connecting the top and bottom members of each section together in spaced relation; and tension connecting means joining the sections of the bottom member, the tension connecting means between at least one pair of ad jacent sections being positively adjustable in length; whereby an upward camber may be produced in the upper surface of the structure such that deflection produced by the ultimate superimposed working load will substantially neutralize said camber.

2. A detachable sectional carrier for use in building construction comprising: a plurality of sections; each of said sections including an upper by the figures of .0.15" to chord; ands a lower? chcrdt spaced: therefrom;

means? interconnecting said upper. andlower" chords; each".twomeighboring. sections including. tramsversewsurfaces at the ends of: theupper 5 cho1 'ds;.to:sabut fortransmission offcompressive stresses. under. superimposed loads; releasable means joining said sections at their. upper chords;

andipositive means infinitelyadjustable between. predetermined; limits interconnecting. neighbor- 5 ing: sections: adjacent said lower chords; whereby arrsupward camber'may be produced in theupper surface of the carrier suchthatdeflection pro duced by th ultimatesuperimposed working =1oad willisubstantially neutralize said camber. l

sections. each forming a i unitary constructional partzan'd including .i an upper chord and a: lower.

chord spacedtherefrom, each such section fur:- ther including means interconnecting saidupper aIldiiIOWEI" chords, and transversesurfaces at ther'ends: of: the "upper chord forming abutments t for'tran'smission of compressive stresses under superimposedt loads; releasable means joining-i 2.5 saidsectionstat their upper chords; and positive adjustable means including connections between the :sectionsh-adjacent said lower chords, at least i one rofrsaidconnections being flexible; whereby an upward camber may be produced in the upper surface of the carrier such that deflection produced by the ultimate superimposed working load will substantially neutralize said camber.

4. A. detachable sectional carrier for concrete forms and the like comprising: at least two sections each including an upper chord and a lower chord and elements interconnecting these two chords; each two neighboring sections further including transverse surfaces at the ends of their upper chords providing thrust bearings for transmission of compressive stresses in a direct line between the neighboring sections when under load with said transverse surfaces in contact with one another; releasable means positively joining adjacent sections at said transverse surfaces; and turnbuckles interconnecting neighboring sections adjacent said lower chords; whereby a positive camber may be produced in the upper surface of the carrier such that defiection produced by the ultimate superimposed working load will substantially neutralize said camber.

5. A detachable sectional carrier for concrete forms and the like comprising: a plurality of sections each forming a unitary constructional part and including an upper chord, a lower chord, and interconnecting elements, each such section further including transverse surfaces at opposite ends of its upper chord providing thrust bearings for transmission of compressive stresses when the carrier is under load; releasable means positively joining said sections at their upper chords; and flexible means including turnbuckles interconnecting the sections adjacent said lower chords; whereby a positive camber may be produced in the upper surface of the carrier such that deflection produced by the ultimate superimposed working load will substantially neutralize said camber.

6. A carrier as defined by claim 5 in which the upper chords of the several sections of the truss are formed of flat plate-like elements which include downwardly extending marginal flanges and in which the marginal flanges at the ends of the sections provide said transverse thrust bearing surfaces.

3.1 .Andetachable sectional carrier for usein building-construction comprising: a plurality of '7. A detachable sectional carrier for concrete forms and the like comprising: a plurality of sections of varying length for selective assembly to provide a plurality of combinations to vary the overall length of the carrier, each such section forming a unitary constructional part and including an upper chord, a lower chord, and interconnecting elements, each such section further including transverse surfaces at opposite ends of its upper chord providing thrust bearings for transmission of compressive stresses when the carrier is under load; releasable means joining said sections at their upper chords; and flexible means including turnbuckles interconnecting the sections adjacent said lower chords; whereby an upward camber may be produced in the upper surface of the carrier such that deflection produced by the ultimate superimposed working load will substantially neutralize said camber.

8. In a detachable sectional falsework carrier for use in building construction, a section comprising: an upper compressive chord member having substantially greater transverse width than depth; a lower tension chord member; means joining said members in fixed spaced relation; means substantially co-extensive in width with and positioned at each of the ends of the upper chord member affording a releasable butt connection for transmission of compression loads between similar adjoining sections; and means positioned at each of the ends of the lower chord member affording, when connected to a similar section, a joint positively adjustable longitudinally of the section; whereby two or more of said sections may be joined to provide a falsework carrier which may be cambered upwardly so that deflection produced by the ultimate superimposed Working load will substantially neutralize said camber.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,112,542 Loser Oct. 6, 1914 1,163,641 Cummings Dec. 14, 1915 1,233,743 Arndt July 17, 1917 1,670,462 Macomber May 22, 1928 1,830,060 Kandle Nov. 3, 1931 1,836,126 Luce Dec. 15, 1931 1,964,208 Leland June 26, 1934 2,167,413 Bartlett July 25, 1939 FOREIGN PATENTS Number Country Date 55,873 Switzerland Mar. 4, 1911

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