Improved Construction of Imbedded Metal Supports for Structures in which Concrete or Equivalent Material is used, such as for Floors, Ceilings, Roofs, Stairs, Bridges and the like.
Year: 1898

page_text: Date of Application, 10th May, 1898-Accepted, 9th July, 1898
COMPLETE SPECIFICATION.
Improved Construction of Imbedded Metal Supports for Structures
in which Concrete or Equivalent Material is used, such as for
Floors, Ceilings, Roofs, Stairs, Bridges and the like.
I, JOHANNES MUELLER, of No. 1, Jootystrasse, Berlin, Germany, Manufacturer,
do hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention relates to an improved manufacture of floors, ceilings, roofs,
stairs, bridges and such like structures in which concrete or equivalent material
is used and it consists mainly in the imbedding in the concrete or like material
used for forming the body of the floor &c., of an iron structure of peculiar
formation and arrangement, being mainly constructed of zig-zag shaped, flat iron
bars or bands placed upon edge, which are directly or indirectly clamped together
whereby the strength of the floor &c. against fracture by overloading is greatly
increased.
The said zig-zag bars are situated between parallel bearing bars which consti-
tute the connecting medium when the zig-zag bars are indirectly connected, but
which, when these are directly connected, are also combined therewith.
The iron skeleton framing formed by the zig-zag iron bands and the bearing
bars, after having a boarding attached to its under side at a distance of about 1/2
inch therefrom has concrete, composed preferably of gravel and cement, stamped
into its spaces, so as to surround the said iron parts on all sides, and thus protect
them both from rusting and from fire-heat.
In this combination the concrete is only subject to compressional strains, while
the iron frame-work takes the tensional strains, thus forming with the concrete
a compound body of very great strength.
Fig. 1 of the accompanying drawing shews a sectional perspective view of a
floor or other structure constructed according to my said invention, in which the
zig-zag iron bands E, running parallel with each other, as to their general
direction, are not directly fixed together, but are connected indirectly through the
medium of bearing bars T, the connection of these with the zig-zag bands, being
effected by clamps K formed by preference of iron bands which are advan-
tageously wound right round the contiguous parts of E and T to be secured
together, so as to form, as it were, a ring round them.
In the construction of Fig. 1 the bearing bars T rest upon the bottom flanges
of the joists or girders D, but this is only shewn by way of example, as in many
constructions of ceilings, arches &c., the bars must rest upon the upper flanges
of the girders or joists, as shewn in the section at Figure 2 and corresponding
plan at Figure 3.
In this construction the zig-zag bands E are secured directly to each other by
means of the band clamps K, which at the same time embrace the bearing bars T.
In both the above arrangements, and in particular in the second one, the tensional
strains to which the bars T are subjected are transferred to the entire skeleton
frame, this being effected- practically uniformly in all directions, so that the
action may be defined as a radial transmission of the tensional strains.

page_text: The sections at Figs. 4 and 5 shew that the bearing bars T need not necessarily
be horizontal or straight, but that they can be more or less curved, and either be
made with an arch-like upward curvature as at Fig. 4, or with a downward
curvature as at Fig. 5; and generally speaking, the arrangement of the bearing
bars can be variously modified in this respect, being made with a greater or less
inclination according to the nature of the structure in which they are employed.
In whatever may be the arrangement employed, the connection of the zig zag
bands can be either as at Fig. 1, or as at Fig. 3, and in some cases these two kinds
of connections can be combined. In place of bearing bars of a flat band section
such as above described, bearing bars may be made of angle iron, or of sheet iron
bent into angular form, or of a tee section as shewn in section at Figs. 6 and 8,
as also in the plan views at Figs. 7 and 9. The arrangement of the zig zag
bands E at Fig. 7 corresponds to that at Fig. 1, while that at Fig. 9 is similar to
that at Fig. 3, but in these cases it is preferred not to pass the clamping bands K
right round the hearing bars, but to make them of a looped form, as at Figs. 6
and 8 which only embrace the vertical limb of the angular or T shaped bearing
bars, at the same time embracing the contiguous parts of the zig zag bands E.
The T shaped bearers will of course be formed by rolling, which may also be
the case with the bearers of angular section.
In practice the bearing bars are, generally arranged from 43 ins. to 6 ins.
apart, and the straight parts of the zigzag bands have a length of about from 5
to 6 ins., so that the cellular spaces between these parts only have an area of
about 8 square inches. On ramming in the concrete, it is very strongly com-
pressed in these spaces, as it cannot escape laterally, so that by this means, should
the supporting bottom boarding be removed too soon, any falling out of the
concrete and consequent destruction of the floor &c. would be prevented, as the
iron framing can readily support the fresh mass of concrete. Should a heavy
body fall upon the floor after the boarding had been removed and before the
concrete had set, only the concrete of one or two of the small cells would be forced
out, without causing the destruction of the entire floor &c., which is of consider-
able importance. The zigzag bands being firmly clamped to the bearing bars,
they prevent the buckling or twisting of the latter, and, as above stated, they
effectually distribute the strain caused by a local excessive load over a large area
of floor, which is also of great importance.
The above described improved construction of concrete floors or the like, being
also fire proof, is applicable with advantage to a great number of structures, such
as factories, barracks, warehouses, dwelling houses, reservoirs, swimming baths,
cellars &c., also roofs, stairs and bridges can be effectively constructed of concrete
by this means.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In the construction of floors, ceilings, roofs, and other structures with con-
crete filling, the use of an imbedded iron supporting frame-work consisting of
zig zag iron bands placed on edge connected together either directly or indirectly
by clamping devices, substantially as described.
2. In floors, ceilings, roofs, and other structures having an iron supporting
frame-work, such as is referred to in the first claim, the arrangement of the
zigzag bands between iron bearing bars secured thereto by clamping devices, sub-
stantially as described.
ABEL & IMRAY,
Agents for the Applicant.