IMPROVEMENTS IN GIRDERS
Year: 1885

page_text: We, RUDOLPH AUGUST STOFFERT, of 4 West Regent Street, Glasgow, Lanark-
shire, Contractor for Iron Work and Fireproof Structures, and THOMAS DYKES
of 65 West Regent Street, Glasgow, aforesaid, Architect, do hereby declare the
nature of our Invention for "IMPROVEMENTS IN GIRDERS," and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement :-
The object of our Invention is the production of girders of iron, steel, or other
metal, to fulfil the general requirements of a girder, and also for combination with,.
and support of floors, or other structures; said girders being of such construction as
to secure a maximum of strength combined with lightness, and the employment of
few differing or uninterchangeable forms of parts in the construction of any one
individual girder.
The improved girder consists of an upper and a lower flange of T iron or steel
or other metal which are connected together by a series of straps or braces of L, T,
channel or other suitable section, having a flat surface to bear on the webs of the
upper and lower T shaped flanges to which they are bolted, riveted, or similarly
secured. Such connecting straps or braces may be made of various curvilinear
form, their form and disposition however being such as to leave between or within, or
between and within them at intervals, spaces through which, without necessitating:
the undoing of the main parts of the girder, bars of iron or steel, of varied and
suitable section and dimensions may be fitted transversely within the body of the
girder to rest on the lower flanges of a series of the girders, and form a strong
structure such as the floor of a building, and to support masonry, brickwork, or
concrete materials.
When joists of wood are fitted within the body of the girder, instead of bars of.
iron or steel, the upper flange of girder will in general require to be unbolted or
removed for their introduction, but this will be unnecessary in the applications?
illustrated in Figures 3. and 9.
The curvilinear connecting strap or braces may also be disposed in such manner
as to give a maximum carrying power to the girder for general purposes for which
it may be found suitable.
The upper and lower flanges of the girders may, in each case, be either rolled to
aT shape, or be built to such shape from flat bars combined with bars of Lor
other sections

page_text: "
Various modifications of girders formed in accordance with our invention are
illustrated in the accompanying drawings. Figures 1 and 2 are cross sections and
Figure 3 is an elevation of part of an improved girder formed of an upper and a
lower flange of T section, connected by curvilinear straps and braces which are
rivetted or bolted on opposite sides of the central web of the T flanges. The
opposite and alternate braces are in the form of arches and inverted arches, a form
which may be suitably termed an "arch-and-invert structure. Into spaces left
between each pair of braces, joists of wood are passed transversely, the joists being
rested on the lower T flange of the girder, and being cut to fit over and under the
central webs of the T flanges, the upper edges of the joists being flush with the
upper edge of the girder. To permit of placing the timber joists into position in
such a form of girder, as is illustrated in Figures 19, 24, and 33 where such joists
cannot otherwise be introduced, the upper T flange is unbolted, the joists fitted in
place, and the upper flange laid over them and bolted to the connecting braces.
The joists may be fitted to rest against the vertical sides of the "arch-and-invert
braces or they may be held between side plates passing partially round the joists
and bolted to the braces as indicated in Figure 3.
"
Figures 4, 5, and 6 are an elevation and transverse sections of a similar form of
arch-and-invert girder fitted with transverse joists of iron or steel. The joists in
this case rest on the web of the lower T flange and on the sides of pieces of channel
or angle-iron section bolted to the web, and joists of various section may also be
passed, as shown, through the centres of the arch-and-invert braces.
Figures 7, 8, and 9 are views of an arch-and-invert braced girder in which the
braces are of U shape and are narrower than in the previous modifications. This
girder is shown fitted with wooden joists and the same form of girder is shown in
Figures 10, 11, and 12 fitted with iron or steel joists. Figures 13, 14, 15, and 16
are horizontal sections taken on the plane of under surface of web of top T shaped
girder flange, illustrating various modes of fitting wooden and iron joists in such
girders. Figures 17, 18, 19, 20 and 21 illustrate a form of girder in which the
.arch-and-invert braces which partially cross each are bolted together and form a
sinuous structure. The bolts which secure the crown of arched braces may here be
'conveniently arranged to work clear of the timber joist, which in such cases would
not require to be cut or checked to receive bolt heads, as shown in Figure 32.
A somewhat sinuous form of structure is also shown in the girder illustrated in
Figure 22, 23, 24, 25, and 26 in which the limbs of the U shaped braces are inclined,
and the adjacent braces rest on each other. Figures 27, 28, 29 and 30 are horizontal
sections of the same. In these examples the joists are fitted within the arch-and-
invert braces instead of between adjacent braces. Figures 31, 32, 33, 34 and 35
illustrate a form of arch-and-invert braced girder corresponding to that shown in
Figures 7 to 12 but having the joists fitted within the curved braces. Figures 38
and 39 are horizontal sections of the same. Figures 36 and 37 are respectively an
elevation and transverse section of a girder formed with arch-and-invert braces
which cross each other on opposite sides, and in which there is no provision for the
insertion of transverse joists, this construction, as also that shown in Figures 19, 20,
24, 25, 33, and 34 when these have their timber joists or iron bars removed, are
all adapted for a carrying girder merely. Figures 40 and 41 are sections of braced
girders in which the T flanges are built of bars or plates of iron, steel, or other
metal, and Figures 42 and 43 are sections showing built flanges of iron or steel
combined with wood, with which in like manner the form of flanges shown in
Figures 40 and 41 may also be similarly combined. Figures 44 and 45 are
respectively an elevation and transverse section of a girder somewhat different
from that shown in Figures 36 and 37 in which the arch-and-invert braces on the
opposite sides are put wider apart, so that the bolts which secure the crown of
their arches also secure their ends, and is suitable for a lighter class of girders.
In each of the modifications illustrated the arch-and-invert structure may be
varied by dispensing with the braces on one side of the webs of the T flanges or by
fitting the braces alternately on each side.

page_text: 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
First. The improvements in girders herein described and illustrated.
Second. A girder formed by an upper and a lower flange of
section connected
by a web consisting of arch-and-invert braces substantially as herein described and
illustrated.