Improvements in Sheet Metal Lathing and in Machinery for Producing the same.
Year: 1898

page_text: Date of Application, 22nd Mar., 1898-Accepted, 4th June, 1898
COMPLETE SPECIFICATION.
Improvements in Sheet Metal Lathing and in Machinery for
Producing the same.
I, JOHN ALFRED WILLMORE, of 187 to 193, Union Street, Borough, in the
County of Surrey, Engineer, 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:
As a substitute for wood laths to receive plaster for ceilings and partitions,
sheets of metal stamped or perforated in various ways have been used.
I prepare sheets of steel, iron, or other metal for this purpose by making long
perforations in pairs in such a manner that the metal is cut or slit along one side
of each perforation only and is then forced downwards so that the displaced metal
is left standing nearly at right angles to the sheet, each pair of perforations have
a thin strip of metal left between them and the portions forced down are on the
further side of each perforation from the central strip so that the parts forced down
in each pair of perforations forms a dovetail key for the plaster.
The perforations are as above stated arranged in pairs and the alternate rows of
pairs of perforations overlap one another, and the portions of metal forced down
from the perforations being thus caused to overlap gives considerable rigidity to
the sheet which is still further stiffened by giving flutes or corrugations between
the rows of perforations.
The sheets are made into the required form by rolling and the machine consists
of a pair of rollers as illustrated by the accompanying drawing in which
Fig. 1 is a plan of the underside of a portion of the lath made as herein described
in which z¹, 2, 3 are the flutes or corrugations, x, x, x are the strips of metal left
between each pair of perforations and y, y, y the portions of metal displaced and
forced up nearly to a right angle with the sheet in the process of making the
perforation, the perforations between each pair of flutes 21, 22 break joint with and
overlap those of the adjacent pair of flutes 23, 23.
Fig. 2 is a section of same along the line AA in Fig. 1.
Fig. 3 is a cross section along the line BB in Fig. 1.
Fig. 31 is a front elevation of the machine.
Fig. 4 is a transverse section of the machine on the line CC in Fig. 3¹.
Fig. 5 is an enlarged view of the corrugating or fluting discs.
Fig. 6 is an enlarged part vertical section through the machine on the line DD
in Fig. 4.
Fig. 7 is an enlarged view of the slitting knives and forming discs.
The machine consists of two mandrels or shafts the top shaft being driven by a
belt and suitable gearing and the bottom one from the top shaft by the toothed
wheels 1, 1, so that both revolve at the same speed.
On these shafts are mounted a series of discs and knives which together make
up rolls for forming the flutes and perforations. Taking the top roll I have the
discs g, g which are keyed on to the shaft W and which have a V shaped projection
on the edge, on each side of these discs and fixed to them are the slitting and

page_text: alternating that is, taking the knife e Fig. 7 with the teeth at top and bottom, the
next knife to it fixed on the other side of the disc g would be turned slightly
round so that one of the spaces would come at the top, this results in the knives
between any pair of discs 9 and therefore between any pair of flutes having their
teeth and spaces opposite to one another.
The discs g are made wider at their centre than at their circumference and thus
a space is left between each pair of knives e, e as shown in Fig. 6.
In these spaces on the lower side of the top roll are placed the bars K, K, which
act as strippers or takers off.
In the bottom roll I have the discs h, h which are keyed on to the shaft t, these
discs have a V shaped recess turned into their outer edge of exactly the same
shape as the V projection on the discs g of the upper roll; on each side of the
discs h are the forming discs f, f, fixed to them in a similar manner to the knives
on the upper roll so that on any disc 7, the forming disc f on one side will have one
of its projections central to a space of the forming disc f on the other side.
The discs are also made wider at the centre than at the circumference and
thus a space is left between each pair of former discs fif, and in these spaces on
the top side of the lower roll are placed the bar knives J, J.
The knives J, J and the strippers K, K are kept at proper intervals by suitable
distance pieces and are supported at the ends by bolts passing right through them
and the side frames of the machine, they are still further supported in the centre
by the bosses of the discs g and h.
When the rolls are in their proper working position the horizontal portions of
the outer periphery of the discs g and h are only separated by a distance equal to
the thickness of the metal to be operated upon and the V projection on the disc g
fits into the V recess in the disc h and forms the flutes or corrugations as the sheet
of metal passes between the rolls; the teeth or projections on the knives e fit into
the recesses in the forming discs f and as the sheet of metal is passed into the
machine in the direction of the arrows in Figs. 4 and 7 between the bars K, J,
it is caught between the teeth of the knives ee and the edges of the bar J and
slit and as the rolls revolve the sheet is carried forward and by the teeth of the
knives e passing through the sheet the metal is pushed back from the
slit into the space between that portion of the knives e that project
beyond the discs g and the discs h on the lower roll and in this
way the perforations and projections y, y in Figs. 1, 2 & 3 are formed, the
sheet having passed the centre of the rolls the bars K come into use as strippers to
prevent the sheet being carried round the upper roll by the teeth of the knives e, e.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1st. The sheet metal lath as herein described and illustrated.
2nd. A roller machine for producing this lath consisting of fluting, slitting and
forming discs built up into rollers with fixed bottom knives and strippers sub-
stantially as described.
D1 1 001
35 L 1000