IMPROVEMENTS IN AND RELATING TO THE CONSTRUCTION OF BRIDUES.
Year: 1882

page_text: LETTERS PATENT to Henry Harris Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
ΟΙ IMPROVEMENTS IN AND RELATING TO THE CONSTRUCTION OF BRIDUES.'
A communication from abroad by Gustave Eiffel, of Paris, France.
ΟΙ IMPROVEMENTS IN AND RELATING TO THE CONSTRUCTION OF
A communication from abroad by Gustave Eiffel, of Paris, France.
DRIDGE.
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 5th January 1882.
HENRY HARRIS LAKE of the Firm of Haseltine Lake & Co., Patent Agents
Southampton Buildings London. "IMPROVEMENTS IN AND RELATING TO THE
CONSTRUCTION OF BRIDGES." [A communication from abroad by Gustave Eiffel,
of Paris, France.]
This Invention has for its object the construction of bridges by means of separate
parts all of which are similar to one another, and by the employment of which, in
a suitable number, any distance compatible with the resistance of the materials
whereof they are composed, may be spanned over as hereinafter described.
This system of construction is especially applicable for the following purposes.
To provide temporary bridges or passages which can be put up rapidly for armies
in the field.
To provide permanent bridges or passages for ordinary roads, or for railways of
small width in localities where the labor of special workinen is not easily obtained,
as for instances in the colonies.
The distinctive characteristic of my Invention consists in the provision of separate
parts or elements all like one another, which, when arranged and secured together,
allow of variable length and resistance, according to span, being given to the
principle girders of the bridge.
These parts or elements are composed of triangular pieces which cannot become
distorted or get out of shape, and are arranged in the shape of truss-girders or
lattice-trusses; they are jointed to one another by means of pins or rods so situated
as to secure the lateral and partial superposition of the parts the lower portions of
which can be united, the one to the other by special pieces.

page_text: By means of these parts I can thus make the principal girders of a bridge whose
variable span happens to be, by reason of the arrangement, a multiple of that of one
half of an element or part. I can also arrange these parts or elements so as to
superpose them in the direction of the height, by making a girder of a height which
is a multiple of that of the elements or parts.
I have represented in the accompanying Drawing as specimens only, different
views of the parts or elements arranged according to my Invention.
Figure 1 represents a front elevation of one element or part.
Figure 2 is a diagram representing in elevation, and plan a bridge composed of a
single element or part.
Figure 3 is a similar diagram of a bridge composed of two elements or parts.
Figure 4 is a similar diagram of a bridge of five clements or parts.
Figure 5 represents a tie-rod for connecting the lower portion of the separate
elements or parts.
In these Figures the same letters indicate similar parts.
As shown in the Drawing, the elements or parts are essentially formed of
isosceles triangles a a, with standards b; the other interior pieces may or may not
be used according to circumstances. These elements or parts are made of pieces of
iron or steel of any convenient section. Each of the extremities of the elements or
parts has at c connecting pins or rods; their central part receives also, at d, d, the
extremities of the elements or parts which are placed in juxtaposition by super-
imposing them partially when it is found desirable to increase the span of the
bridge.
The elements or parts are moreover connected with one another, at their lower
portion, by tie-rods which are connected with apertures e, e, drilled for the purpose
in the triangular element or part. These tie-rods may be arranged in any
convenient manner; the one represented in Figure 5 is formed of two parts f, f,
connected by a central nut g engaging with right and left handed screw threads
which allows of a sufficient tension being obtained. They can also be made of
figured iron with an arrangement of apertures suitable for ensuring the tightening.
A bracing arranged in any convenient manner connects transversely the girders
and ensures their firmness.
The flooring proper may be easily fitted either at the upper portion or at the
lower portion of the elements or parts or between the two.
I may vary the dimensions and forms of the elements or parts as also the nature
of the component materials without departing from the principle of my Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Harris Lake in the Great Seal Patent Office on the
5th July 1882.
HENRY HARRIS LAKE of the Firm of Haseltine, Lake, & Co., Patent Agents
Southampton Buildings London. "IMPROVEMENTS IN AND RELATING TO THE
CONSTRUCTION OF BRIDGES." A communication from abroad by Gustave Eiffel, of
Paris, France.
This Invention has for its object the construction of bridges by means of
separate elements or parts, all of which are similar to one another, and by tho
employment of which, in a suitable number, any distance, compatible with the
resistance of the materials of which they are composed, may be spanned over, as
hereinafter described.
This system of construction is especially applicable for the following purposes, viz.:—
To provide temporary bridges or passages which can be put up rapid for armies ;
and to provide permanent bridges or passages for ordinary roads or for railways of
small width in localities, where the labor of special workmen is not easily obtained,
as for instance in the colonies.
The distinctive characteristic of the said Invention consists in the fitting up of
separate parts or elements all similar to one another, so that when arranged and
secured together as hereinafter described, they allow of variable length and
resistance, according to the span, being given to the principal girders of the
bridge.
These parts or elements are composed of triangular pieces which are not liable
to become distorted or get out of shape, and are arranged in the shape of trussed
girders or lattice-girders; they are jointed to one another by means of pins or rods,
80 situated as to secure the lateral and partial superposition of one part upon
another, the lower portions of the elements or parts can be united one to the other
by special pieces.
By means of these parts or elements I can make the principal girders of a bridge
whose variable span is, according to its arrangement, a multiple of that of one-
half of an element or part. I can also arrange these parts or elements so that they
may be superposed one upon another to form a girder of a height which is a
multiple of that of one of the elements or parts.
In the accompanying Drawing are illustrated as specimens only, different views
of the parts or clements arranged according to the said Invention.
Figure 1 represents a front elevation of one element or part.
Figure 2 is a diagram representing in elevation, and plan, a bridge girder
composed of a single element or part.
Figure 3 is a similar diagram of a bridge girder composed of two elements or
parts.
Figure 4 is a similar diagram of a bridge girder composed of five elements or
parts.
Figure 5 represents a tie-rod for connecting the lower portion of the separate
elements or parts.
Like letters indicate the same parts throughout the Drawing.
As shewn in the Drawing the elements or parts are essentially in the form of
isosceles triangules a a with standards b; the other interior pieces 61 6' may or
may not be used according to circumstances. These elements or parts are made of
pieces of iron or steel of any convenient section. Each of the extremities of the
elements or parts has at c connecting pins or rods; their central part receives

page_text: at d d the extremities of the elements or parts which are placed in juxtaposition
by superimposing them partially when it is desired to increase the span of the
bridge.
The elements or parts are moreover connected with one another, at their lower
portion, by tie-rods which are provided with apertures corresponding to the holes
ee drilled for the purpose in the triangular element or part. These tie-rods many
be arranged in any convenient manner; the one represented in Figure 5 is formed
of two parts ff connected by a central nut g engaging with right and left handed
screw-threads which allows of a sufficient tension being obtained. They can also
be made of iron having a number of apertures suitably arranged for ensuring the
tightening of the said rods. A bracing arranged in any convenient manner connects
the girders transversely and ensures their firmness.
The floor or platform of the bridge may be easily fitted either at the upper
portion or at the lower portion of the elements or parts or between the two.
I may vary the dimensions and forms of the elements or parts as also the nature
of the component materials without departing from the principle of the said
Invention.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent and the manner of performing the same I wish it understood
that I claim:-
First The improved manner of forming bridge-girders by the combination
therein of the triangular elements or parts constructed and arranged together
substantially as set forth.
Second: A triangular element or part substantially as shewn and described, to
be used in the construction of bridge-girders as, and for the purpose, specified.
In witness whereof I the said Henry Harris Lake have hereunto set my
hand and seal this Fifth day of July in the year of our Lord One
thousand eight hundred and eighty two.
HENRY H. L
DARD.
(LAS.)