The present application relates to truss systems used in the construction industry, and in particular, relates to a column hung truss system for forming of concrete floors.
Flying form trusses are used to form concrete floors in multi-story structures. Some flying form truss systems transmit the poured concrete load directly to the floor slabs below and in fast construction cycles, the concrete floor below may not be fully cured. For this reason, reshoring of the lower concrete floor may be necessary to transmit the loads to a slab which is fully cured. Reshoring takes additional time and also limits the access to some lower levels which are effectively cured.
To overcome the above problems, it is known to use column mounted flying form truss systems designed to transfer the concrete load to the columns as opposed to the lower floors. Column mounted truss systems allow full access to the lower floors and the follow-up trades can be working on any floors which have been previously poured. With this arrangement, the construction cycle can be reduced.
Column mounted flying truss systems are most commonly used with flat slab construction but can accommodate shallow internal beams and spandrel beams. Any projection from the slab soffit increases the stripping distance the support jacks must lower the truss to allow removal.
Flying form systems typically use two large I-beams which run parallel to the building support columns with the I-beams being supported by shoring jacks secured to the columns. The shoring jacks are adjustable in height and typically have a roller associated therewith to allow lowering of the I-beams and sliding of the truss out of the formed bay. These I-beams have a series of transverse beams secured to and extending perpendicular to the I-beams. A series of runner beams which typically support a plywood deck are secured and extend perpendicular to the transverse beams.
The construction design of the building in combination with the expertise of the contractor typically determine whether a column hung truss system or a shoring frame truss system will be used. Column hung truss systems are often used for condominium and hotel construction, particularly when a short construction schedule is needed.
The transverse beams are of a length which is primarily determined by the width of the bays used in the building. The bay width is the distance between the columns. Surprisingly the bay width of different buildings varies substantially and thus different lengths of transverse beams are required. It is known to use composite transverse beams formed using U-shaped channel sections placed in back to back relationship and secured in an overlapping adjustable manner. Typically mechanical fasteners are used to secure the channels to form the appropriate length of transverse beams. It is desirable to produce relatively stiff transverse beams such that the spacing between the beams can be large, thereby reducing the number of transverse beams required and reduce the weight of the system. It is desirable that the overall weight of the flying truss be reduced to ease the movement thereof and to accommodate the crane capacity used for the building construction.
The present invention provides improvements to the transverse beams and improvements to truss systems used in concrete forming.
An extruded elongate metal component according to the present invention comprises in cross section, a hollow section having a top securing section first and second opposed side securing sections and a bottom securing section. The top securing section includes a recessed bolt slot extending the length of the structural component. The side sections have complimentary shapes with the first side securing section including a recess extending the length of the structural component, the second side securing section includes a projecting section sized for snug receipt in the recess of first side section. The bottom securing section includes at least one downwardly projecting securing flange extending the length of the structural component.
According to an aspect of the invention, the extruded elongate structural component is an extruded aluminum alloy component.
In a further aspect of the invention, the hollow section of the structural component is of a generally rectangular cross section.
In yet a further aspect of the invention, each side section has a series of holes extending therethrough and aligned with the holes through the other side section.
In yet a further aspect of the invention, the at least one downwardly projecting securing flange is two downwardly projecting securing flanges disposed in parallel relationship either side of the center line of the bottom section.
In yet a further aspect of the invention, the securing flanges include a series of securing holes passing therethrough and spaced in the length of the structural component.
In yet a further aspect of the invention, the recess in the first side section is a shallow U-shaped section which dominates the first side section and the projecting section of the side section includes opposed upper and lower shoulders for engaging sides of the shallow U-shaped section.
An assembled structural beam, according to the present invention, comprises a top chord and a bottom chord which are mechanically connected by a series of diagonal connecting members. The top chord includes on an upper surface, a longitudinally extending bolt slot. The bottom chord includes on a bottom surface, a longitudinally extending bolt slot. Each of the top chord and the bottom chord have two opposed side surfaces with a shallow channel recess in one side extending the length of the chord, and a complementary projection on the opposite side extending the length of the chord and sized for receipt in the shallow channel recess. Each of the top chord and the bottom chord are extruded components and include a securing flange which cooperates with the diagonal connecting members to secure the top chord to the bottom chord.
In an aspect of the structural beam, vertical connecting members are included.
In a preferred aspect of the invention, the top chord and the bottom chord of the assembled structural beam are of the same cross section.
In yet a further aspect of the invention, the top chord includes a hollow cavity extending the length thereof.
In yet a further aspect of the invention, the chords and the diagonal connecting members are extruded aluminum alloy components.
In yet a further aspect of the invention, the diagonal connecting members are secured to the chords using mechanical fasteners.
In yet a further aspect of the invention, the top chord includes on an upper surface a longitudinally extending bolt slot and the bottom chord includes on a bottom surface, a longitudinally extending bolt slot.
The present invention is also directed to a header beam which is adjustable in length. The header beam comprises two beam sections secured one to the other in an overlapping manner. Each beam section is an assembled structure having a cop chord, a bottom chord and a series of connecting members secured thereto between. The top chord and the bottom chord of the beams include interfitting surfaces which maintain longitudinal alignment of the beam sections relative to each other. The beam sections further include a series of holes in the top chord and bottom chords and a plurality of structural fasteners passing through aligned holes in the chords which in combination with the interfitting surfaces, mechanically secure the beam sections.
An adjustable in length header beam according to an aspect of the invention, as each of the beam sections being of the same cross section.
In yet a further aspect of the invention, the top chord and the bottom chord are of the same cross section.
In a further aspect of the invention, the chords are formed by extrusion and each chord has an extending member at one side and a corresponding receiving channel on the opposite side thereof.
In yet a further aspect of the invention, the header beam is stackable with like header beams with the interfitting surfaces engaging to partially maintain the stack of beams.
Preferred embodiments of the invention are shown in the drawings, wherein:
As shown in
One beam section 44 is shown in FIG. 4. This beam section includes a top chord 20, a bottom chord 22 and a series of diagonal bracing members 24 and a series of vertical members 26. Members 24 and 26 are mechanically secured to the top and bottom chords. Each of the chords is of the same structure and has a series of holes 22 extending in the length of the chords. These holes pass directly through the chords and are used to mechanically fasten two sections, one to the other.
A top chord 20 is shown in
The flanges 40 and 42 are positioned inwardly of the sides 34 and 36 with the entire mechanical connection of the connecting members 24 and 26 located in a non interference position when two sections are secured, one to the other, as shown in
As can be seen, the top and bottom chords are of the identical section and merely reversed in orientation. If damage occurs to either the top chord or the bottom chord, a new chord member can be inserted. It can further be appreciated that damage may have occur to only part of the chord and a portion of the chord may be salvaged for another application.
FIG. 11 and
As shown in
The transverse beams 6 are of a design such that the beam sections cooperate with one another along the top and bottom chords to oppose racking of the sections when the beams are loaded. The beam sections are mechanically secured one to the other and allow for ready adjustment in length of the transverse beams. As can be appreciated, for a given building structure, the bay width is essentially constant and therefore, the truss can be used for forming of the bay floor and then repositioned for forming of the floor thereabove. In many cases, the bay sizes will be somewhat standardized and there will be no requirement to vary the length of the transverse beams. In some cases due to the particular building design, the bay width may be somewhat unusual and thus, the transverse beams can be adjusted in length, to allow formation of the truss of appropriate width.
Details of the column hung jack assemblies are shown in
It is preferred that the composite structural beams 44 and 46 be made of an extruded aluminum alloy components or similar lightweight high strength component. The top chord and the bottom chord are of the identical structure and the diagonal connecting members and the vertical members are tube members with relatively thick sidewalls which have the holes for connecting of the member to the chords and thinner end walls.
The transverse beams 6 can be spaced along the main beams 4 anywhere from 64 inches to 108 inches apart. The actual separation of the transverse beams 6 will be determined by the thickness and weight of the slab being poured.
The flying form truss, due to the large size thereof, is assembled onsite and is dismantled once the building is complete. The individual components are transported to and from the site and between jobs are stored in a construction yard. The transverse composite beams can be stacked sideways, one on top of the other, and interfit to maintain the stack. This stacking is particularly convenient with the individual beam sections. The projecting, elongate rail 52 is received in a U-shaped receiving channel of an adjacent beam section. This stabilizes the stack and is helpful in transportation and storage.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
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3180460 | Liskey, Jr. | Apr 1965 | A |
3778175 | Zimmer | Dec 1973 | A |
4102108 | Cody | Jul 1978 | A |
4106256 | Cody | Aug 1978 | A |
4350318 | Gallis | Sep 1982 | A |
5729944 | De Zen | Mar 1998 | A |
6519908 | Masterson et al. | Feb 2003 | B1 |
6553736 | Montanaro et al. | Apr 2003 | B2 |
Number | Date | Country |
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840 435 | Jun 1952 | DE |
14 34 335 | Apr 1971 | DE |
0 380 953 | Aug 1990 | EP |
988 705 | Aug 1951 | FR |
2 036 150 | Jun 1980 | GB |
Number | Date | Country | |
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20030205019 A1 | Nov 2003 | US |