as IN FIREPROOF CONCRETE ROOFS FLOORS AND ROOF PAVEMENTS follows
Year: 1884

page_text: I ARTHUR WELLESLEY LAKE of 37 Hogarth Road Earls Court in the County
of Middlesex do hereby declare the nature of the Invention for "IMPROVEMENTS
" to be as
IN FIREPROOF CONCRETE ROOFS FLOORS AND ROOF PAVEMENTS
follows:-
This Invention relates to improvements in fireproof concrete roofs floors and
roof pavements.
The object of this Invention is to lessen cost of construction and make the
structure capable of admitting light without thereby exposing the premises to the
spread of flames in case of fire and consists of-
First. A self-supporting concrete composite beam-arch.
Second. A self-supporting concrete composite beam-arch formed with openings
after the manner of an illuminating grating made to admit light.
Third. A self-supporting concrete composite bem-arch formed with openings
after the manner of an illuminating grating in combination with glass to shut out
the weather and admit light.
Fourth. A concrete arch formed with openings after the manner of an illuminating
grating to admit light.
Fifth. A concrete arch formed with openings after the manner of an illuminating
grating in combination with glass to shut out the weather and give light.
In constructing illuminating concrete arches hitherto I have employed gratings
of some kind either metal or brick as strengthening cores to the arches.
The present Invention differs from those in respect to cheapness for by the
present method I rely wholly upon the concrete in combination either with tie rods
or beams.
The Invention in its best form is that of a self supporting beam-arch-by which
I mean that I make floors roofs and walking surfaces or pavements of concrete
arches that have no need of beams to rest upon; the spandrils or haunches of the

page_text: arches having tie rods incorporated within the concrete material that give to these
parts of the arches the character of beams that is to say the tie rods or metals
located at or near the bottom of the haunches are in tension while the concrete
portion of the launches at the top and above the neutral axis are simultaneously
in compression when the beam or construction is under strain.
The present Invention is an improvement upon the structures composed of
concrete and tie metals set forth in Mr. Hyatt's work entitled "Some Experiments
with Concrete and Iron as a Building Material" copies of which are to be found
in the libraries.
The nature of the improvement is that the floor or construction is made in the
form of arches instead of being made solid and of course heavier when solid.
This is the Invention as a self supporting beam-arch; and when made with
openings to give light such openings being blocked with glasses the Invention is
then an illuminating beam arch.
But when the tie metals are dispensed with and iron beams employed as in the
common mode of making arch floors then the Invention is simply an illuminating
concrete arch wherein its simplicity and cheapness is the Invention, the combination
being merely concrete and glasses to make the illuminating arch.
Dated thin ord do of
1004

page_text: I ARTHUR WELLESLEY LAKE of 37 Hogarth Road, Kensington in the County
of Middlesex do hereby declare the nature of the Invention for "IMPROVEMENTS
IN FIRE-PROOF CONCRETE ROOFS, FLOORS, AND ROOF PAVEMENTS" and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-reference being had herein to the accompanying
Drawings (one sheet) making part of this Specification :-
My Invention relates to fire-proof concrete roofs, floors, and roof-pavements,
including area coverings.
The object of my Invention is to lessen cost of construction and make the
structure capable of admitting light without thereby exposing the premises to the
spread of flames in case of fire; and it consists of, first, a self-supporting concrete
composite beam-arch; second, a self-supporting concrete composite beam-arch
formed with openings, after the manner of an illuminating-grating, to admit light;
third, a self-supporting concrete composite beam-arch formed with openings after
the manner of an illuminating-grating in combination with glass to shut out the
weather and admit light; fourth, a concrete arch formed with openings, after the
manner of an illuminating-grating, to admit light; fifth, a concrete arch formed
with openings, after the manner of an illuminating-grating, in combination with
glass to shut out the weather and admit light.
Figure 1. is a perspective view representing a self-supporting concrete composite
beam-arch, a a indicating the beam portions outside of, and a¹ a¹ a¹ indicating the
arch portion between the broken lines b b. Fig. 2 represents the same construction,
but formed with openings, after the manner of an illuminating-grating, and set
with glasses to give light. Fig. 3. represents a roof, floor, pavement, or construction
made of self-supporting concrete composite beau-arches. Fig. 4. represents a roof,
floor, pavement, or construction made of self-supporting concrete composite beam-
arches formed with openings after the manner of an illuminating-grating to admit
light. Fig. 5. represents an illuminating concrete arch designed for being carried
upon outside supports or beams. Fig. 6. represents a roof, floor, pavement or
construction made of illuminating concrete arches carried upon supports or beams.
A. indicates concrete. B indicates tie metals. B₁ indicates web metals.
B' indicates supports or beams. C. indicates tie rods. D. indicates light-holes.
E. indicates glasses. c indicates nuts on tie-rods. d. indicates cross wires of tie
metals. i indicates the under or flaring portion of the light holes.
Figs. 1 to 4 illustrate my Invention in order to save the cost of iron beams, the
Invention consisting in the introduction of tie-metal strength into concrete-arches
construction in manner as I have heretofore employed it in the construction of solid
concrete floors.
Where web metal B₁ is shown, it is merely to illustrate the method of its
employment. It would not be employed on one side of the arch only, but used for
all the arches and in the beam portions of all. The purpose of web metals is to
add rigidity where the beam-span is great between the wails or supports.
The effect of tie metals placed in the haunches of the arches is to convert that
portion of the structure lying outside the broken line 6 b, and marked a a, into a
beam, the compress ve portion of which is the concrete and the tensile portion of
which is the tie metal; but it may be reasonably supposed that the curved portions
lying within and between the broken lines b b also enter into compressive
resistance to the load when the beam is under strain.

page_text: "
The rule for calculating the size and strength of the tie metals is the same as for
web and flange beams, examples in illustration of which may be found in my
work entitled An Account of some Experiments with Portland Cement Concrete
combined with Iron as a Building Material," copies of which work are to be found
in the Patent Office library and in other libraries, both in England and in the
United States.
By the ordinary modo of building, large openings or well-holes are cut through
roof or floor to admit light, the closures of which are not fire-proof, such openings
materially aiding in the spread of flames in case the building takes fire. Where
such roof or floor is constructed of concrete arches it is evident that if the same
area of light opening be divided into small apertures and spread over a larger
surface, as I have represented in Fig. 4, no such danger can happen.
Fig. 2. represents the perforated concrete arch closed by glasses, in the ordinary
manner of making patent-light work; but Fig. 4 represents a structure where the
light-holes are left open and ready to receive glass for the purpose of shutting out
the weather:
My object in representing a structure of open light-holes is to explain that I do
not limit the closing of these light holes to glass blocks that plug them like a cork;
but in some cases I overlay the surface with plate, sheet, or pane glass, suitably
glazed, in sashes made in some cases to be opened for ventilation. In other cases
I mold ribs of concrete on the face of the roof and glaze the glass between them.
In Figs. 3 and 4 I have represented the end arches only with tie-rods. They
thus become abutments for the other arches and make tie-rods for them unnecessary.
To protect the tie-rods themselves against fire, I surround them with a coating
of plaster-of-paris, concrete, or other fireproofing material, as represented in
Figs. 1 and 2.
Fig. 5. represents an illuminating concrete arch designed to be employed with
metal beams, and Fig. 6 represents a roof, floor, or construction made by combining
such arches with beams, as indicated at B².
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. A self-supporting concrete composite beam-arch, substantially as and for the
purposes herein set forth and illustrated.
2. A self-supporting concrete composite beam-arch formed with openings, after
the manner of an illuminating-grating to admit light.
3. A self-supporting concrete composite beam-arch formed with openings, after
the manner of an illuminating-grating, in combination with glass to shut out the
weather and give light.
4. A roof, floor, pavement, or structure made of self-supporting concrete composite
beam-arches, substantially as and for the purposes herein set forth and illustrated.
5. A roof, floor, pavement, or structure made of self-supporting concrete composite
beam-arches fora.ed with openings, after the manner of an illuminating-grating, to
admit light.
6. A roof, floor, pavement, or structure made of self-supporting concrete composite
beam-arches formed with openings, after the manner of an illuminating-grating, in
combination with glass to shut out the weather and admit light.
7. A concrete arch formed with openings, after the manner of an illuminating-
grating, to admit light.
8. A concrete arch formed with openings after the manner of an illuminating-
grating, in combination with glass to shut out the weather and admit light.
9. A roof, floor, pavement, or structure made of concrete arches formed with
openings, after the manner of an illuminating-grating, to admit light, in combination
with supports or beams, substantially as and for the purposes berein set forth and
illustrated.

page_text: 10. A roof, floor, pavement, or structure made of concrete arches formed with
openings, after the manner of an illuminating-grating, in combination with glass
to shut out the weather and almit light, when the same are combined with supports
or beams, substantially as and for the purposes herein set forth and illustrated.
In witness whereof I, the said Arthur Wellesley Lake, have hereunto set my
hand & seal, this 21** day of April in the year of our Lord One thousand
eight hundred & eighty four.