US3182772A - Telescopic metal girders - Google Patents

Description

Mayxll, 1965 L.. ALzlARI TELEscoPIc METAL GIRDERS Filed Jan. 18. 1961 1w f is l Nm\\ w\ w1 NM u 11. e. w mH\ U r m m i. S Y m S. H N

` 3,182,772 TELESCGPIC lt/IETAL GIRDER Louis Alzar'i, 2S Bd. Carabacel, Nice, France Filed Jan. 18, 1961, Ser. No. 83,4051 Claimspriority, application France, Jan. 21, 1960, Patent 1,245,439l 1 Claim. (Cl. 189'-37) My invention lhas for its object improvements in telescopic metal girders serving in reinforced concrete structures, chiefly to be used for floors.

Such girders provided with extensions, allow cutting out all the staying means used hitherto and their interest lies chiey in the fact that they may serve for spans or bearingdistances of various lengths, which spans may be comparatively large.

system including the girder and its extension in its eX- panded condition, as required for use, is limited in the z-case of large bearings, as a consequence of the straining to which the .system is subjected, chiefly at the point lWhere its component elements are interconnected. It j is thereforenecessary to give them a suitable resistance, the good condition ,of'their connection governingthe l rigidity ofthe whole system. resistance vof the girders as-requirerd, it isV therefore nec- However, the length of the In order to increase the essary, in the case of comparatively large bearings, 'to resort to girders and extensions for the latter which are both provided throughout their length with a suicient height, since theinertia of such elements depends chiefly on their height and this leads to heavy and bulky structures and, consequently, to many drawbacks,'to wit: a

high cost price and diicult transportation handling and erection. Itis possible, it is true, to resort to lighter structures, but thesystem would then risk showing av too largeflexibilityw -It would be therefore of advantage toiresort to much lighter structures associated with oblique stays and ver- However, VsuchV elements whichfare conventional for frameworks including ordinary girders having a predetermined length spanning the space separating two bearing surfaces, are not applicable inter alia to the girders including a plurality of elements telescopically sliding inside each other to match various spans or bearing distances, by reason of the compressional forces which have a tendency to make such elements slide inside one another.

Now, my invention has for its object to allow the application of oblique stays to girders provided with extensions, with all the advantages of a light structure, a reduction in cost price and an easy handling, while the system obtained remains however rigid and subjected as a whole to a camber suiting the conditions of use.

My invention consists in providing a girder including a plurality of elements adapted to suit various bearing distances, with a removable runged stay engageable at one end through one of its rungs on one of the girder elements, while its other end is provided with screwcontrolled clamping means or the like, in association with a runged locking system operating endwise through a stop in a direction parallel with the axis of the girder system, to urge the elements forming said system against` each other.

United States Patent Vthe uprights 4a-4b as illustrated in FIG. 1.

3,182,772 Patented May 11, 1965 M' Ice I have illustrated in the accompanying drawings two preferred embodiments of myinvention. In said drawings:

FIGS. l to 4 Vshow a girder provided with a single extension, FIG. `l being an elevational view of the whole system and FIG. 21a` front view `of the stay, illustrated separately.

FIGS. 3 and 4 are large-scale transverse cross-sections of details `of the girder system through lines III-III and IV,-IV of FIG. l showing respectively the location ofrthe extension slidably carriedV inside the girder and the` locking through a single. double-acting Wedge operating both longitudinally and vertically.

,and FIG. 9 a cross-section through line IX-IX of FIG. 6.

Turning now to FIGS. V1 to 4, it is apparent that the girder P has its upper flange constituted by an inverted channel iron 1 connected by a trellice-work 2 with a lowerV iange 3V sloping downwardly and forming -a stationary stay between the outer end of the girder and the upright 4 which acts as a'king-post. The end of girder P adjacent the king-post is thus deeper than the other end of girder P. Said king-post upright includes in practice four-bars, of which two are welded to each side of the upper flange 1, as shown at 4a-4b and 4'a- 4b, the four bars being all connected together through their lower ends, so as to form a unit incorporating or t provided with a hook system C. At a suitable level,

the four bars carry and are rigidly secured through welding or otherwise to a horizontal plate 5 adapted to support the extension R, -as `disclosed hereinafter; said extensionis constituted by `an-I iron extending horizontally `projecting blocks or cleats 8 are secured to the underside of the lower ange of the extension. Lastly, a tie means or stay T which is independent and removable, is provided as shown in FIG. 2, in the shape of a runged ladder 9, between two stringers 10. One of the ends of said stay or ladder is provided with clamping means constitutecl, for instance, by a screw 11.

The system including the main girder and its extension is rst brought to the desired length, so that it may rest on the desired bearing surfaces, while two successive cleats 8 arelocated to either side of the gap separating It is sufli cient to slide over the plate 5 through the aperture between the uprights of each pair 4a-4b or 4a-4b a locking member 12 which locks the extension R against any longitudinal sliding with reference tothe beam V1. The stay T is then secured through hooking of one of its rungs over the lower end C of the king-post unit 4, in a manner such that the clamping screw 11 may be in a position for which it engages a stop provided for this purpose, at the end of the extension or at a point near said end of the extension. Upon screwing down of said screw 11,'the stay is tensioned and it is thus possible to give the system including the girder and its extension the rectilinear shape or the camber required.

It is also necessary to ensure a vertical clamping of the I iron forming the extension in contacting relationship with the inverted channel iron forming the member 1 of 3 the girder. It is suicient, to this end, for the locking member 12 to have its lower and upper surfaces forming a locking wedge member, as illustrated in FIG. 4, in order to obtain as simply as possible the locking in a horizontal direction against relative sliding of the two elements of -the compound girder and extension system and a clamp- Y is ,then inserted between the lower ends C1 and C2'of the f upright king-posts of the two terminal girders, while the locking of the three elements, both horizontally and vertically, is obtained as precedingly by the locking members or wedges 121 and 122.

In FIGS. 6 to 9, the extension R forms a trellice-work and the same is the case for the girder P', but the extension is higher than the girder P. The web and the depending sides of the upper inverted U-shaped iron 1 forming the upper ange of the girder holds slidingly, as. in the preceding case, the upper ange of the extension i length of said stay. In order to lock the two elements of .the system both against longitudinal slidingV and relative rocking movements, there is provided in the case of said second embodiment, a series of openings in the sides of the upper U-shaped flanges of the girder and of its extension, whilera simple pin is inserted through any desired cooperating openings which are brought into registry, as clearly shown in FIG. 9. It should be remarked Y y that the use of this Vimproved arrangement furthers con- Siderably the dismantling ofthe girder with reference to itsextension; as a matter of fact, once the floor has set, it isl sucient Vto releaseV gradually the stay, so as to prevent the pin from being subjected any longer to the action of the load and to allow its ready removal; a subsequent tightening of the stay produces a sliding of one element of the system with reference to the other, which allows their removal. In order to prevent the rocking of one of the elements with reference to the other, one

2. of them, say the extension in the case illustrated, includes, beyond its end engaging the upper ange 1 Yof the girder and beyond the king-post 4', Aa projection 13b bearing against the girder, as shown more particularly in FIG. 7. Obviously, many other arrangements may be resorted to in the execution of my invention, according to the applications to be considered and the conditions to be satistied or to be selected as more advantageous in the different cases, said modifications lying obviously within the 'scope of the accompanying claim.

What I claim is: A telescopic girder for supporting timbering for reinforced concrete, comprising a'rst beam having a horizontal top chord and an inclined bottom chord so that the first beam has one end deeper than the other, upright king post means at said deeper end, a second beam telescoping at one end with said deeper end of said rst beam, said second beam having .a series of downwardly depending longitudinally spaced cleats disposed lengthwise thereof, said king post means having an aperture extending laterally therethrough, a locking wedgemember removably disposed in said aperture and extending removably between an adjacent pair of said downwardly depending cleats thereby adjnstably positioning said first and second beams in any of a plurality of longitudinally adjusted positions relative to each other, tie means interconnectirlg the lower end of said king post means below said wedge and the end ofV said second beam remote from said first beam, and means tensioning said tie means.

References Cited by the Examiner UNITED STATES PATENTS,

1,233,743 7/17 Arndt 189-37 2,403,853 7/46 Fromson 189-37 2,415,461 2/ 47 Causey l82*222 2,95 11564 9/60 Meyer 189-37 2,974,762 3/ 61 Hunnebeck 189--37 3,023,863 3/62 Klaus 189-37 3,059,738 10/62 Lutz 189-37 FOREIGN PATENTS 218,497 11/5 8 Australia. 1,098,651 3/55 France. 1,125,298 7/56 France.

173,953 `7/06 Germany.

384,996 10/ 23 Germany.

RICHARD w. COOKE; n., 'Primary Examiner.

ACORNELIUS, D. ANGEL, JACOB L. NACKENOFF, l Examiners.

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