IMPROVE- MENTS IN THE CONSTRUCTION OF METAL LATHS FOR USE IN THE FORMATION OF CEILINGS AND PARTITIONS AND FOR OTHER USEFUL PURPOSES"
Year: 1883

page_text: LETTERS PATENT to George Middleton Edwards of N° 54 Gresham Street in
the City of London EC. Public Accountant for an Invention of "IMPROVE-
MENTS IN THE CONSTRUCTION OF METAL LATHS FOR USE IN THE FORMATION
OF CEILINGS AND PARTITIONS AND FOR OTHER USEFUL PURPOSES"
PROVISIONAL SPECIFICATION left by the said George Middleton Edwards
at the Office of the Commissioners of Patents on the 27th August 1883..
GEORGE MIDDLETON EDWARDS of N° 54 Gresham Street in the City of London
E.C. Public Accountant IMPROVEMENTS IN THE CONSTRUCTION OF METAL LATHS
FOR USE IN THE FORMATION OF CEILINGS AND PARTITIONS AND FOR OTHER USEFUL
PURPOSES
"3
My Invention has for one of its objects the construction of Metal Laths to be
used in the formation of Ceilings and Partitions in Dwelling Houses and other
Buildings in which, in some cases, wooden Joists or Rafters are used to carry the
Floors, Ceilings and Partitions
For this purpose I use thin strips of sheet iron, (of about 26 to 28 Birmingham
Wire Guage) or other metal, about two inches wide and fourteen or fifteen inches
long or more. Along each side of these strips, pieces advantageously about three
eighths of an inch square are cut out at regular intervals, so as to make the strips
present serrated edges.
A groove, taking up about one inch of width of metal in its formation, is then
indented in the strips along the centre of their entire length and the edges of the
groove are afterwards, by mechanical means, brought so close together as to cause
the groove to assume a form of which the open end is sufficiently narrow in
relation to the rest of the groove, as to permit of materials, inserted therein in a
plastic condition, being mechanically retained there when they shall have become
set or hardened.
.
The strips of metal then present the form of a narrow mouthed groove with a
portion of metal acting as angle iron on the outer side of each of its lips, and
serrated owing to the pieces having been cut out as above described.
By this arrangement a very large amount of holding surface is, afforded for:
bearing plastic materials such as those ordinarily used in the construction of
Ceilings and Partitions in Houses or other Buildings.

page_text: These Laths I propose to make use of for the purpose required by nailing or
otherwise fastening them, through the centre of the groove at each end, to a Floor
or other Joist, each Lath being placed, when used in construction of Ceilings, with
the open side of the groove downwards, sufficiently close to another as to bring
their serrated edges within about a quarter of an inch of contact
The plastic materials on being applied fill the grooves and slip through the
interstices caused by the gaps between the serrated edges, thus causing nearly half
the lower surface of a ceiling to be firmly keyed and the remainder to be so held
in small and nearly equal sections as to have its weight uniformly distributed over
the entire surface.
The objects which I desire to effect by this method are, that the use of wooden
laths, which are combustible, will be entirely obviated-The risk of Ceilings falling
will be much reducod, if not altogether obviated and they, as also Partitions, can
by the use of suitable plastic materials be made practically fire resisting at very
small extra cost.
The form of groove may be varied, so long as the main feature, of its mouth
being narrow in comparison with its other dimensions, is maintained for tho
purpose already stated.
My Invention has also for its object the use of another form of Lath requiring
less metal in its construction than the foregoing.
"This is made of strips of metal about one inch and a half wide and fourteen or
fifteen inches long or more, one side of which to the extent of about five sixteenths
of an inch is bent as angle iron, and the strip is then cut across its breadth to
within one quarter of an inch of the angle in slits half an inch apart more or less,
the metal between the cuts is then pressed outwards at right angles to each side
(right and left) alternately, to afford serrated edges with holding power as before
described and the Laths are nailed or otherwise fastened to the Floor Joists
through their angle iron top which acts as a backbone to the Lath for the purpose
of giving it rigidity. These Laths will be chiefly applicable to construction of
Ceilings.
My Invention has also for its object the use of Laths made as those first described
herein but larger in every way and without serrated edges-The grooves of such
laths I fill with plastic or other suitable materials thereby giving solidity and
enabling the Laths to be used as Sash Bars for glazing purposes, the glass in such
case being laid upon the inside of the angle iron which is on the outer sides of
the lips of the grooves and fixed by putty or other suitable composition.
By using Metal which has been subjected to well known processes for preventing
oxidization, the necessity for painting such Laths will be obviated.
In any case where desirable or advantageous, portions of all these Laths can be
perforated to give additional holding power on plastic materials, and they can.
bo rivetted or otherwise fastened together so as to form lattice work.
When using these Laths for the purpose of protecting the bottom flanges of
Rolled Iron Beams or of other Joists or Girders from the offect of fire, I use means
for supporting them by metal loops formed and secured in any convenient manner
so long as they are capable of having the ends of the Laths inserted therein on
each side of and below the edges of the lower flanges of the Beams, so as to cause
the Laths to form a substantial network underneath the flanges with ability to
sustain suitable plastic materials for more or less resisting fire.
I form the Laths first described by means of a suitable stamping machine which
at one motion cuts the serrated edges on each side of the metal strips and makes a
curved indent in the metal. The curve is then altered to the shape desired by the
indented strips of metal being placed in a press and force applied so as to make
the indented curve close upon a metal_core or mandril of the requisite shape and
dimensions for the purpose required. In some cases however a mandril or core is
not necessary.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Middleton Edwards in the Patent Office on the 26th February
1884.
GEORGE, MIDDLETON EDWARDS of N° 54 Gresham Street in the City of London
EC in the County of Middlesex. Public Accountant IMPROVEMENTS IN THE
CONSTRUCTION OF METAL LATHS FOR USE IN THE FORMATION OF CEILINGS AND
PARTITIONS AND FOR OTHER USEFUL PURPOSES
My improvements consist in using thin Sheet Iron or other suitable metal, for
the purpose of making Laths which, by the form given to them, shall combine
great strength and rigidity together with ability for mechanically holding some
portion of the plastic materials used, in combination with Laths, in the construction
of Fire-resisting or other Ceilings or Partitions in Dwelling houses and other
Buildings, and also for giving increased facility for keying or supporting a larger
proportion of the plastic materials thus used, than is usual under existing
systems.
For the purpose of obtaining this proposed result, I use thin strips of sheet
iron, of about 26 to 28, Birmingham Wire Guage, or other suitable metal, about
two inches wide, more or less, and from fourteen to thirty six inches long, more
or less.
Along each side of these strips, pieces of metal of about three eighths of an inch
square, or larger if requisite, are cut out at regular intervals so as to make the
strips present notched edges on each outside edge.
A groove, taking up about one inch or more of width of metal in its formation,
is indented in the strips of metal along the centre of their entire length, and the
edges, of the groove are, by means hereinafter described, brought sufficiently close
together as to make the groove assume a form, of which the opening throughout
its entire length is sufficiently narrow in relation to the rest of the groove as to
permit of materials, inserted therein in a plastic condition, being mechanically
retained there when they shall have become set or hardened.
These Laths, I propose to make use of for the purpose required, by nailing or
otherwise fastening them, through the centre of the groove at each end of the
Lath, to a floor or other joist, each Lath being placed, when used in the construction
of Ceilings, with the open side of the groove downwards.
In using the Laths they are advantageously placed along side of each other about
one quarter of an inch apart, so that each tooth of the notched edge shall be
opposite to the gap or opening in the next Lath placed on either side, thus reducing
largely the width of the plaster key.
The plastic materials, used in combination with these Laths, on being applied
by the ordinary method of trowelling or otherwise, slip through the interstices or
gaps between the notched edges of the Laths and by proper manipulation from
above, entirely embed the laths in plastic materials, thus preventing oxidization
or rusting of the metal.
The lower face of the Ceiling is sustained by a portion of the plastic materials.
being held in the groove of the laths, and by adhesion of much of the remainder of
the plastic facing to the exposed lower surface of the plastic materials which have
been used above and between the Laths, in the formation of the upper side of the
Ceiling.
The objects which I desire to effect by this method are, that the use of com-
bustible wooden laths will be avoidable. The risk of Ceilings falling will be much
reduced, if not entirely obviated, and they, as also Partitions between rooms,, can

page_text: by the use of suitable plastic materials be made practically fire-resisting at very
small extra cost above that of ordinary lath and plaster constructions of this
charactor.
The form of groove in the Laths may be varied, so long as the main feature of
its mouth being narrow in comparison with its other dimensions is maintained.for
the purpose of retaining plastic materials therein:
My Invention has also for its object the manufacture and use of a Lath of
another form, requiring less metal in its construction than the foregoing.
This Lath is made of strips of thin metal, about one inch and a half wide and
about fourteen inches long or more, one side of which, to the extent of about five
sixteenths of an inch is bent over as angle iron, and the strip is then cut, on its
other side, across its breadth to within about a quarter of an inch of the angle, in
slits half an inch apart, more or less.
The metal between the cuts in then pressed outwards at right angles to each
side (right and left alternately) to afford notched edges with holding power, some-
what similar to those already herein described, and the Laths are made use of by
being nailed or otherwise fastened to the Joists through their angle iron top,
which acts as a back bone to the Lath for the purpose of giving it rigidity-These
Laths will be chiefly applicable to the construction of ceilings.
I also propose to attach or connect Laths, made as those first herein described,
to each other by inserting them endways into light T, angle or flat iron of suitable
section, in one side or edge of which openings shall be cut or punched of such form
as will permit of the Laths, when inserted therein, being keyed by reason of the
base of the groove in the Laths, already described, being wider than the mouth of
the opening punched in the T, angle, flat or other iron
By afterwards covering the whole of the Metal Laths thus used, with cement
or cement concrete, a slab will be produced suitable for many useful purposes and
of great durability.
By crimping the upper face of cement in the slabs thus formed, by means of a
suitable rollor, irregularity of surface will be produced, when required, at nominal
cost.
Such slabs, when strongly made, I propose also to use for floors or walking
surfaces and they can be made fire-resisting by use of suitable materials.
My Invention has further for its object, the use of Laths made as those first
herein described and of suitable size, and not necessarily made with notched edges,
for the purpose of Sash bars and for glazing with glass. The grooves of such
Laths I propose to fill with plastic or other suitable materials, thereby giving
solidity. The glass is laid upon the inside of the angle which is on the outer sides
of the lips of the groove and is fixed by putty or other suitable composition or
fastening.
I also propose to use Latlis, advantageously of the form first herein described,
for the purpose of enabling Woodwork, such as Doors, to be covered with a coat of
fire-resisting material of appreciable thickness, say, half an inch or more. By nailing
or otherwise fastening the Laths on and to the wood work with the open side of
their grooves outwards, cement and other plastic materials can be firmly attached
and form a protection to wood work and cause it to present the outside appearance
of concrete or artificial stone work.
By using the laths in conjunction with wooden or Iron frame work, suitably
constructed, Cottages, Emigrants Houses and other similar small Dwellings or
Lodges can be conveniently and quickly erected in situations where materials for
making Sand concrete are available.
By using Metal which has been subjected to well known processes for preventing
oxidization, the necessity for painting any of the Laths or Metal herein described
will be obviated, in cases where such protection may be deemed desirable or
advantageous
. In any case where desirable or advantageous, portions of the Laths used can be
perforated to give additional holding power on plastic materials, and they can be

page_text: rivetted or otherwise fastened- together at their ends so as to form longer lengths,
or lattice work.
:
When using the grooved Laths in conjunction with Wood work, I use iron or
steel Nails specially constructed with long and flat heads, with a broad shoulder.
By this arrangement the nails can be driven up to tlie shoulder without damaging
the groove of the Lath through which they are driven, for the purpose of fixing it
at each end to the Wooden Joists or other wood work.
When using these Laths for the purpose of protecting the bottom flanges of
Rolled Iron Beams or of other Joists or Girders from the effects of fire, I use means.
for supporting them by metal loops formed and secured in any convenient manner,
so long as they are capable of having the ends of the Laths inserted therein on
each side of and below the edges of the lower flanges of the Beams, so as to cause
the Laths to form a substantial network underneath the flanges, with ability to
sustain suitable plastic materials for more or less resisting fire.
Now in order that my improvements may be clearly understood and readily
carried into practice, I will proceed to illustrate the same by and describe the
Drawings hereto annexed.
Fig. 1. shows a Lath. A side view. B, end view and C, plan. This Lath is
formed out of sheet metal and has a dovetail groove down the middle for
giving transverse strength and the edges are alternate projections and spaces of
about equal sizes.
Fig. 2. is another form of Lath. A sile view. B. end view and C, plan. This
is formed from a strip of metal by bending over short lengths on each side
alternately, and then giving to the face a surface consisting of projecting pieces of
metal and spaces suitable for holding up plaster: The back is turned on one side
at right angles to the middle web to give transverse strength and enable the lath
to be nailed to wood work.
Fig. 3, is a sectional view, shewing Laths of the description in Fig. 1. used in
forming a Ceiling.
Fig 4, is an arrangement for using Laths of the same description, for forming a
Ceiling when Iron joists are used. The Laths are nailed to strips of wood D. D. D
running parallel with the joists, the strips by the Joists are nailed to fillets.
E. E. lying on the bottom flange of the Joists, and the middle strip is carried by
cross pieces such as F.
In the Drawing these cross pieces, F, are shewn strong enough for carrying the
floor also.
Fig. 5 shews another method of using these Laths in combination with Iron
Joists. Pieces of wood, G. G, the ends of which are cut to fit the flange of the
Beam are put up so as to extend across the ceiling at right angles to the iron
joists, and at a distance apart equal to the length of the laths, the laths are then
nailed to these and the plastering completes the ceiling.
Fig. 6. shews the way in which I propose to use the Laths in fire proof buildings,
when no wood is to be used in forming the Ceiling. For the purpose of holding
up the laths, I punch spaces of a dovetail, or other form suitable for the lath in
use at proper intervals along the edge of pieces of angle iron (see H) these spaces
being the size of the dovetail or other groove on the laths. These angle irons are
then laid on the bottom flange of the Joists, so that the edges in which the spaces
have been previously punched come below the bottom of the Joists. The cross
bars K are then put into place and serve to keep the angle irons in position. The
Laths are pushed lengthways into the spaces in the edge of the angle iron and
the ceiling is ready for plastering. The fire-resisting quality of such a Ceiling
may be increased by covering the top with suitable concrete to any desired
thickness.
Figures 7 and 8, illustrate the machinery. I advantageously use for manufacturing
the laths of the form in Fig 1. Fig 7, being a transverse section of the stamping
machine and Fig 8, a transverse section of the dovetail forming machine.
The die L, of the stamping Machine (a plan of short length of it being given

page_text: at M) is formed with a groove along the middle, and one side has a series of
projecting pieces corresponding to the projections on the edge of the lath. The
cross head N carries two hardened steel cutters O and P. O. being formed with
teeth which fit into the spaces between the projections on the die and P being a
straight cutter.
A sheet of metal, the width of which is the length of the lath to be made, is
fed into the machine on the right side and pushed on after each stroke to touch
the guide bar. R. in which position when the cross-head descends again, a piece,
which is a half inade lath is cut off. By these means there is no waste of metal,
as the pieces taken out to form the spaces in the edge of one side of a lath form
the projections in a side of the succeeding lath and vice versa. The projections on
the die will, on reference to the plan M be seen to be slightly tapered so that the
sheet metal after being sovered by the teeth of the cutter, O, may be drawn
freely to form the groove, and for the same reason the cutters. O. and P, are set
slightly out of the vertical so that they may not hold the sheet iron in case any
burr is formed in the cutting.
The Lath, as it comes from the stamping Machine only differs from a completed
Lath in that the groove is wider at the open side than at the other. To complete
the Lath, it is pushed end ways into the Machine, of which Fig 8 is a transverse
section. The dovetail is formed by the steel plates S. S. being pressed together-
T, is an iron frame which is raised slightly by the eccentrics on the Shaft U, so
that the Laths may be pushed easily into the Machine, it is then brought down to
the position shown in the Drawing to bear against the Lath while the dovetail is
formed.
After a Lath is finished, it is pushed out of the Machine at one end by another
Lath being fed in at the other. All the Machinery above described can be worked
by hand labor or motive power.
Having described the nature of my Invention and in what manner the
same can be performed, I claim as my Invention the general combination and
arrangements substantially as hereinbefore specified and shewn in the Drawings
herewith.
In Witness whereof I have hereunto set my hand and Seal this Twenty fifth
day of February in the Year of Our Lord one thousand eight hundred and eighty
four,
GEORGE MIDDLETON EDWARDS. (L.S.)