Static structures (e.g. – buildings) – Machine or implement
Reexamination Certificate
1999-12-02
2001-12-25
Stephan, Beth A. (Department: 3635)
Static structures (e.g., buildings)
Machine or implement
C052S749100, C052S223120, C052S223800, C052S223130, C052S223100
Reexamination Certificate
active
06332301
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to metal beam structures, particularly steel beams, and also to building constructions including such metal beams.
A particular type of metal beam widely used in the construction of buildings, bridges, and other structures, includes a top flange, a bottom flange, and an intermediate web joining together the two flanges. When such a beam is loaded, the top flange is placed under compression, and the bottom flange is placed under tension. Many techniques have been devised for increasing the load-carrying capacity of the beam, e.g., by prestressing the bottom flange in compression to reduce the bending of the beam under load. Examples of various techniques for increasing the load-carrying capacity of the beams are described in U.S. Pat. Nos. 4,144,686, 5,313,749 and 5,704,181.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a metal beam having a novel construction to increase its load-carrying capacity and/or to reduce the height of the beam as compared to a conventional beam construction for the same load-carrying capacity. Another object of the invention is to provide a building structure constructed with a plurality of such beams.
According to one aspect of the present invention, there is provided a metal beam, comprising: a top flange; a bottom flange; and an intermediate web joining together the top flange and the bottom flange. The bottom flange includes an upper deck and a lower deck joined to the intermediate web and extending in parallel spaced relation to each other. The web extends perpendicularly between, and is joined to, both the upper deck and the lower deck of the bottom flange. The lower deck extends for the length of the web. The metal beam further comprises a pair of transverse members fixed to the lower deck at its opposite ends; and a plurality of tensioning elements extending between the upper and lower decks and anchored to the transverse members to pre-stress the lower deck of the bottom flange, and thereby, to form a double-deck metal beam structure imparting to the beam a high resistance to deformation under load.
According to some described preferred embodiments, the transverse members to which the ends of the tensioning elements are anchored are fixed between the upper and lower decks at the opposite ends of the bottom flange on the opposite sides of the web.
According to another described preferred embodiment, the transverse members to which the ends of the tensioning elements are anchored are fixed between the lower deck and an end structure secured to the intermediate web and the lowered deck of the bottom flange at each of the opposite ends of the bottom flange on the opposite sides of the web.
In all the described embodiments, the space between the upper and lower decks is filled with concrete embedding the tensioning elements.
According to another aspect of the present invention, there is provided a metal beam, comprising a top flange; a bottom flange; and an intermediate web joining together the top flange and bottom flange; the bottom flange including an upper deck and a lower deck extending in parallel spaced relation to each other to form a double-deck structure; the lower deck of the bottom flange being of greater thickness than the upper deck of the bottom flange.
According to one preferred embodiment described below, the intermediate web is of a single wall construction; and according to a second described embodiment, it is of a double-wall construction.
According to another aspect of the present invention, therefore, there is provided a metal beam, comprising: a top flange; a bottom flange; and an intermediate web joining together the top and bottom flanges; the intermediate web being of a double-wall construction defined by parallel spaced walls and including tensioning elements between the spaced walls for prestressing the beam; the space between the parallel spaced walls of the intermediate web being filled with concrete embedding the tensioning elements.
According to a further aspect of the present invention, there is provided a building structure comprising a plurality of metal beams (e.g., steel beams) each constructed as described above; and a plurality of horizontal floor panels supported on the bottom flange upper deck on each of the opposite sides of a pair of horizontal metal beams and joined by cement thereto and to their intermediate webs.
In the described preferred embodiments, the horizontal floor panels are of a thickness equal to the distance between the upper face of the top flange and the upper face of the bottom flange upper deck.
The foregoing features in the construction of the metal beam provide a number of important advantages which are particularly important when the beams are used in building structures of multiple stories. Thus, the above described beam structure provides a relatively high load-carrying capacity for the weight and height of the beam. In addition, making the top flange narrower in width, but greater in thickness, than the bottom flange lower deck enables the floor panels to be of a thickness such that their upper surfaces are flush with the upper surface of the top flange, thereby minimizing the overall thickness of the floor for given conditions of the particular building structure, including the span distance between the columns, the self load, the service load, the construction material used, etc. The distance between the upper and lower decks of the bottom flange, and/or between the two walls of the intermediate web when a double-wall construction is used, can be designed to accommodate the desired number of tensioning elements (e.g., cables) and concrete according to the requirements for any particular application.
Further features and advantages of the invention will be apparent from the description below.
REFERENCES:
patent: 2844023 (1958-07-01), Maiwurm
patent: 3487518 (1970-01-01), Hopfeld
patent: 3753326 (1973-08-01), Kaufman, Sr.
patent: 3913290 (1975-10-01), Billing et al.
patent: 4144686 (1979-03-01), Gold
patent: 5313749 (1994-05-01), Conner
patent: 5511355 (1996-04-01), Dingler
patent: 5704181 (1998-01-01), Fisher et al.
patent: 5848512 (1998-12-01), Conn
Barish Benjamin J.
Chavez Patrick J.
Stephan Beth A.
LandOfFree
Metal beam structure and building construction including same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Metal beam structure and building construction including same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Metal beam structure and building construction including same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2601239