and Buildings, and in the Manufacture of the same.
Year: 1887

page_text: and Buildings, and in the Manufacture of the same.
We RICHARD CHARLES BRAITHWAITE and WALTER KIRK both of Crown Bridge
and Boiler Works Swan Villiage West Bromwich in the County of Stafford Manu-
facturers do hereby declare the nature of our said invention and in what manner the
same is to be formed to be particularly described and ascertained in and by the
following statement :-
This invention has for its object improvements in bent plates used for floors bridges
columns and buildings and in the manufacture of the same by which we obtain a large
amount of strength and a minimum ammount of metal and rivetting in the following
manner.
We take a flat long plate or strip of metal rolled in such a manner as to make a
portion of the centre part thicker than the sides of the strip say about one fifth part of
the centre of the plate and we then bend up the thick part on each side of the centre
to form a trough or double Z section and by this means when several are brought
together with the upper flanges lapping we obtain a girder with top and bottom
flanges thick and the webs thin which economizes the metal and there is less rivetting
than in the case of our previous Patent No. 8266 A.D. 1885.
It will be evident that walls or columns may be made of this section of iron with
economy by fasting the one to the other in a variety of ways such as flanges flanges,
back to back, or flanges to back according the requirements of each case.
In order that our invention may be clearly understood and more easily carried
into practice we have appended hereunto a sheet of drawings upon which we have
illustrated the mode of manufacture and also one application thereof. Other appli-
cations will be easily made by practical men whether for walls or floors bridges or
other buildings.
Figure 1. is a sectional side elevation shewing a broken off elevation of the girder W
of a bridge with a floor built by our new plates in cross section.
Figure 2. A is a plain plate when rolled ready for bending with a parallel swell a'
rolled thereon.

page_text: Figure 3 is an enlarged cross section of several troughs made from section A
Figure 2 and rivetted together with double rows of rivets but the flanges may be
narrower if desired and only one row of rivets used which would in many cases be
sufficient.
Figure 2 B is an alternate plan of a plate before bending which illustrates one
variation in the form of the swell or extra thickness which may be made and
illustrates how this may be varied though the flatter one A would probably be
most used.
Figure 4. is a form which is easily bent from the section B Figure 2 and is very
effective in making up long corrugations without waste.
It will thus be clearly seen the plates A and B are bent in dies or moulds or presses
so that the extra thickness a' or is brought to the bottom part of the trough
floor and takes the tensile strain of any weight coming upon the top whilst the cross
joints composed of the thinner edges and a³ or 2 and 3 takes the compression
which is probably the most favourable position for the rivetted part. These floors
may be made from either wrought iron or steel or other suitable metal. It will be
seen that by turning two troughs face to face a substantial column is formed and that
lattice work diagonals and connecting bars may be revitted between to form walls and
other constructions of various kinds.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is :-
1st. The improvements in bent plates having an extra thickness a or b¹ which
forms the tension number of troughs for the floors of bridges and other buildings
substantially as herein set forth.
2nd. The improvements in bent plates having an extra thickness a¹ or for the
columns and walls of buildings substantially as herein set forth.
GEORGE BARKER,
77, Colmore Row, Birmingham,
Agent for Applicants.