Static structures (e.g. – buildings) – Wall – ceiling – or floor designed for utilities
Reexamination Certificate
2000-08-03
2001-11-13
Friedman, Carl D. (Department: 3635)
Static structures (e.g., buildings)
Wall, ceiling, or floor designed for utilities
C052S220800, C285S154100
Reexamination Certificate
active
06314692
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cast-in concrete, lead-in system for ceilings and walls having a trapezoidally corrugated sheet metal framework and including a lead-in sleeve for receiving one of a tubular conduit and a cable and having at least three outer, circumferentially spaced from each other, fixing points for securing the lead-in sleeve to the trapezoidally corrugated sheet metal formwork.
2. Description of the Prior Art
In contemporary building constructions, formworks formed of trapezoidally corrugated sheet metal that consists of alternating valley and peak regions, found a wide application. Primarily, such formworks are used in substantially horizontal ceilings and are cast in concrete on the site. The trapezoidally corrugated sheet metal remains on the lower side of the ceiling. Often, for subsequent insertion of tubular leads-in through the ceiling, space retainers are mounted in the formwork to provide a concrete-free space for the leads-in.
Likewise, space retainers are provided in double walls. The space retainers for conduits or cable leads-in, before being cast-in concrete, should be reliably secured both axially and angularly with respect to the formwork plane.
U.S. Pat No. 4,261,598 discloses mounting on a formwork of a coupling sleeve instead of a cast-in concrete, space retainer, and a tubular member having a tubular end, which partially projects into the coupling sleeve, and extends through an opening formed in the formwork.
U.S. Pat. No. 4,669,759 discloses fire-retarding leads-in which include an appropriately deformed lead-in sleeve, an end-side outer ring for a temporary mounting, and a ring-shaped sealing which is partially formed of an intermescent material and is mounted inside the lead-in sleeve in the radially widen region of the sleeve. The lead-in is mounted on the formwork and is cast in concrete.
U.S. Pat. No. 5,293,724 discloses a short mounting sleeve with an end surface outer ring for mounting the sleeve on a trapezoidally corrugated sheet metal, and a tubular member extending through the sleeve, the formwork and the concrete ceiling. The end surface outer ring is mounted either in a valley region, on a peak region, or is mounted over two adjacent peak regions. The drawback of this solution consists in that this non-fire-retarding mounting sleeve is characterized by a limited mountability with respect to different, conventionally used formworks because of the difficulty to proper dimension the outer ring. A reliable mounting of such leads-in, in particular of leads-in having small diameters, with respect to precise positioning of the lead-in, is not always possible because of different widths of peak and valley regions of the trapezoidal corrugations of the sheet metal. In the transitional region between peak and valley regions or in a valley region adjacent to the transitional region, a securing of a lead-in is not possible at all or, maximum, a one-sided attachment is possible. Such an attachment, of course, cannot provide a reliable attachment for a subsequent concrete cast-over.
Accordingly, an object of the present invention is to provide a lead-in system for ceilings and walls having a trapezoidally corrugated sheet metal formwork, which can be reliability secured in all positions on all conventional trapezoidally corrugated sheet metal formworks.
Another object of the present invention is to provide a reliably securable fire-retarding lead-in system.
SUMMARY OF THE INVENTION
These and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a system including a lead-in sleeve for receiving a tubular conduit or a cable and having at least three outer, circumferentially spaced from each other, fixing points for securing the lead-in sleeve to the trapezoidally corrugated sheet metal formwork, and at least two stiff locking elements each having a connection element for a formlocking connection with the fixing points of the lead-in sleeve and a mounting element for securing the locking element to peak regions of trapezoidal corrugations of the trapezoidally corrugated sheet metal formwork.
As it follows from above, the leading system according to the present invention, which it later becomes imbedded in concrete, substantially includes a lead-in sleeve having at least three outer fixing points circumferentially spaced from each other and arranged in a plan extending transverse to the axis of symmetry of the lead-in sleeve, with the fixing points being formed, preferably by radial surfaces of an outer ring, and at least two locking elements formlockingly connectable with at least one fixing point. The locking element is advantageously formed as a flat, deflection-resistant member including mounting means for securing the locking member to the trapezoidally corrugated sheet metal, advantageously in its peak region. The lead-in system further includes a tubular member which is later removed. The tubular member is preferably formed of an easily destructable cardboard and is received partially in the lead-in sleeve.
Advantageously, the mounting region of the lead-in system extends over two period lengths of the trapezoidally corrugated sheet metal formwork, with the correspondingly dimensioned locking elements, which are connected with the lead-in sleeve, on its both sides, via the lead-in sleeve fixing points. In this way, in all positions of the lead-in sleeve, a two-sided mounting or securing of the lead-in sleeve over the peak region of the trapezoidal corrugations of the sheet metal formwork becomes possible. For a purposeful shortening of the locking element, e.g., of the edge or comer regions, advantageously predetermined breaking areas are formed therein, e.g., as a row of elongate openings in the locking element formed of metal or as intermittent pressed out area.
Advantageously, the locking element is formed as a flat sheet member having a high deflection and torsional resistance and which can be safely mounted along the plane of the peak region of the trapezoidal corrugations which represents a stepped surface.
The mounting means for securing the locking element to the trapezoidally corrugated sheet metal formwork can be formed as flat surface regions which can be glued to the peak regions of the corrugations, as holes which permit to screw the locking element to the formwork, incisions and openings for forming a welding connection, or a combination of the above-listed means. The foregoing mounting means insure a simply realized, rigid and adequately strong connection of the lead-in system with the formwork.
The fixing points insure at least a three-point positioning of the lead-in sleeve on the trapezoidally corrugated sheet metal formwork, with one fixing point being connected with the formwork by at least one locking element and with at least two further fixing points being connected with the formwork by at least one further locking element. For connection of the locking elements with the fixing points, the locking elements have paired, adapted to each other, connection elements which define a suitable receiving groove for receiving a radial flat region forming a fixing point, whereby a formlocking connection of the locking element with the fixing point is formed. In the discussed embodiment, the connection elements are formed as sheet offset edge regions for receiving a radial flat region therebetween. For fixing points formed as fishplate, the connection element is formed as a correspondingly dimensioned, U-bent edge region that can be hanged up on the fishplate. For simultaneous connection with more than one fixing point, the connection elements are provided on a concavely shaped side of the locking element.
The locking element is advantageously formed of a sheet metal both surfaces of which are protected to prevent any conditions which may cause even a local corrosion during the constructional phase. For a definite positioning of the lead-in sleeve in its fixing points, the side edge of the locking element is provided
Andresen Arndt
Milhes Jean-Louis
Munzenberger Herbert
Friedman Carl D.
Hilti Aktiengesellschaft
Sidley Austin Brown & Wood LLP
Varner Steve
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