IMPROVE- MENTS IN CORE OR SKELETON METALS AS A NEW MANUFACTURE & APPLYING THE SAME (WITH REFERENCE PRIMARILY TO COMBINATION WITH CONCRETE & PLASTIC MATERIALS) TO THE CONSTRUCTION OF FIRE PROOF BRIDGES, BUILDINGS, AND ATTACHMENTS THERETO
Year: 1881

page_text: LETTERS PATENT to Thaddeus Hyatt, of 21, Addison Gardens, N. Kensington,
London, in the County of Middlesex, Inventor, for an Invention of " IMPROVE-
MENTS IN CORE OR SKELETON METALS AS A NEW MANUFACTURE & APPLYING
THE SAME (WITH REFERENCE PRIMARILY TO COMBINATION WITH CONCRETE
& PLASTIC MATERIALS) TO THE CONSTRUCTION OF FIRE PROOF BRIDGES,
BUILDINGS, AND ATTACHMENTS THERETO."
(Void by reason of the Patentee having neglected to file a Specification in
pursuance of the conditions of the Letters Patent.)
PROVISIONAL SPECIFICATION left by the said Thaddeus Hyatt at the
Office of the Commissioners of Patents on the 4th March 1881.
THADDEUS HYATT, of 21, Addison Gardens, N. Kensington; London, in the County
of Middlesex, Inventor. " IMPROVEMENTS IN CORE OR SKELETON METALS AS A
NEW MANUFACTURE, AND APPLYING THE SAME (WITH REFERENCE PRIMARILY TO
COMBINATION WITH CONCRETE & PLASTIC MATERIALS) TO THE CONSTRUCTION
OF FIRE PROOF BRIDGES, BUILDINGS, AND ATTACHMENTS THERETO."
The primary object of my Invention is to provide an economical and convenient
method of constructing concrete fireproof floors and roofs without the use of wood
centerings.
A further object is to form fireproof ceilings underneath the bottom flanges of
the wall beams, by a method at once economical & convenient. A further object
is to provide metallic beam-strength (within the body of the concrete, both to
insure safety during the period of its setting and hardening, and thereafter with
reference to safety in supporting loads and persons passing over it.
My Invention, which is in the nature of a new manufacture or merchantable
article (and is hereinafter referred to as metallic chain lathing), consists in uniting
a convenient number of metal strips, such as hoop iron, into a plate or sheet
composed of solid parts and spaces, the object of the spaces being to furnish a
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page_text: means of keying the plastic to the metal as a completed sheet when made; a
perforated sheet of metal would be its equivalent, as would also be a sheet of metal
corrugated or crimped in manner to form wedge-shaped spaces or channels; and so
also any other form of metal mesh or grating would likewise be equivalents if
combined with supporting bars or carriers, constructed as hereinafter set forth, and
in manner and by methods and for the purposes as hereinafter set forth.
I make no broad claim to the use of metal wattling or wire mesh or gratings in
combination with concrete to form ceilings and floors, neither do I claim broadly.
as my Invention a range of metal laths merely connected together. The
employment of wire cloth in connection with wall beams and concrete to form
ceilings and floors is an old device; and connecting a number of metallic laths or
hoop irons by a system of interlacing with wire is also old.
The metallic chain lathing of my Invention consists of a number of hoop irons
or strips of metal lying parallel to one another but separated by spaces, and
connected into a plate or sheet by means of a rigid metal bar possessing beam-
strength, the combination forming a metallic section of convenient form and shape
to be portable, easily. handled; & readily fixed in position, and that when so
placed and fixed becomes at once beam-strength or bridging to the opening or
space which it spans, and at the same time forms a convenient centering to receive
concrete without requiring any other or further centering; this metallic centering
at the same time furnishing by its keying spaces a means of perfect self-protection
against injury from fire by a coating of fire-proof plastic put upon it on the under
side and held thereto by the keying spaces.aforesaid.
Metallic chain lathing of the above character I propose to make also in the
form of arches, but when made in arch form the limits as to size are not the
same, for metallic chain lathing in arch form may be. employed as flooring from
wall to wall without the intervention of wall-beams; also to span openings in
walls and for shop-fronts, to support the main wall above the principal story in
lieu of the more expensive cast iron arch-girders and rolled beams now in common
use.
With respect to the chain-lathing floor and roof sections a noticeable feature in
my Invention, and one that I attach great importance to, is the form of the rigid
metal bar or joist that connects and carries the laths. The feature I refer to is a
tongue or lip projecting beyond the end of the joist or carrier. at one end, the
opposite end of the joist having no such lip. The design of this lip is to carry a
range of laths underneath the bottom flange of the wall-beams on which the
section rests. By making the sections with one lip only they are easily dropped
into place, the sections of the adjoining bay by their lips underlaping the other
beam, and so on through all the bays and beams of the floor or roof.
Where the construction is one of arches between the wall beams I construct the
arches with a tongue or lip on one side thereof at the bottom to underlap the
bottom flanges of the wall beams on which they rest in manner as above described
with reference to flat sections.
With respect to the chain-lathing as to its mode of construction a noticeable
feature in my Invention, and one to which I attach great importance, is a method of
uniting loose pieces by placing them in the flash along with the pattern joist or
carrier to be moulded, the strips by this method being welded to the carriers in the
process of casting the joist or arch.
With respect to the hoop irons or metal strips as to the mode of employing them
a noticeable feature in my Invention, and one to which I attach great importance, is
placing them at an angle to the line of the carrier in which they are placed, thereby
producing practically the effect of an unbroken sheet, when the section performs
the function of a centering for supporting the concrete, as well as making a
stronger construction in forming walls, partitions, stairways, doors, window shutters,
guards, railings, and other parts and attachments of buildings.
In carrying my Invention into practice I adopt the following method:-Having
selected the hoop-iron, preferably about one inch in width, and from nine to thirty

page_text: six inches or more in length, I make a pattern in wood of the carrier, joist, or
arch to be cast, and insert the strips in such pattern in manner as they are to be
when the casting is completed. The section having been moulded and the patterns
withdrawn the metal strips are left in the sand in position to receive the molten
metal when poured upon them; this operation when completed producing a section
of chain lathing in which the metal blades are nipped and tightly held by the cast
metal joists or arches.
In constructing floors and roofs I place the sections in position between the
beams and put the concrete in the usual manner upon them, as in the case of
other centerings. The ceiling may be put on the underside before or after the
concrete.
In constructing fireproof partitions & walls I proceed in substantially the same
manner.
In making doors, window shutters, stair-ways, railings, and guards or gratings
for areas & vault openings the method is substantially the same as described
above. Where the vault and area-coverings require light I combine glasses with
the concrete, but where both air and light are required I omit the concrete and
glasses.
In constructing bridges I adopt a method substantially the same as in
constructing arches to be used as floors and roofs, a bridge being only a floor of
larger span.
of
In constructing the floors of bridges & the floors & roofs of buildings a part
my Invention consists in employing chain-lathing made with hoop irons laid
flatwise in double range with an intervening space, the metals breaking joints
with each other, a part of the Invention consisting in some cases in bending the
metal laths themselves so as to produce an upper and under ledge to overlap
& underlap each other with spaces between. In other cases I employ laths formed
with under retaining surfaces.
With respect to the metal arch pieces or carriers of the lathing in addition to
the underlip, hereinabove described, for carrying the laths underneath the bottom
flanges of the beams that support the arches; my Invention also includes inner-lips
or projections in the nature of shelves to hold wood cross-joists for nailing the
lathing of the counter-ceiling to.