Year: 1887

page_text: [Partly communicated from abroad by JAMES STONE BLOMFIELD, Merchant, of
22, Basinghall Street, in the City of London, at present residing at Adelaide,
South Australia, and is partly the result of his own Invention or discovery.]
I, ALEXANDER MUIRHEAD, Doctor of Science, Telegraph Engineer, of Cowley
Street, Westminster, in the County of Middlesex, 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:—
My invention has for its object to increase the strength and stiffness or rigidity of
tubular telegraph posts or poles without any serious augmentation of their weight or
cost.
My said invention is more advantageously applicable to posts or poles which are
built of several lengths, tubes or sections. It can, however, also be applied to
posts or poles made of a single tube.
up
I make the said tubes of either circular or oval form in transverse section and I
insert in the lower or larger end of the tube a strengthening or stiffening piece of the
peculiar construction hereinafter described. This strengthening or stiffening piece
mainly consists of a plate or web which, when the said stiffening piece is properly
inserted in the post or pole, extends vertically within the same and diametrically
across the interior thereof in a plane parallel to the telegraph wire, that is to say, it
occupies such a position that it will offer the maximum resistance to the bending
stresses which the post or pole has to withstand. This vertical plate or web is provided
with one or more plates or flanges at right angles thereto, which fit into the tube and
prevent or diminish the liability to failure of the post or pole by collapse.
In the accompanying drawing
Figure 1 is a perspective view of one of my improved strengthening or stiffening
pieces, showing also, in vertical central section, a part of the tubular post or pole in
which it is inserted.
Figure 2 is a transverse section of the said pole and strengthening or stiffening
piece, drawn to an enlarged scale.

page_text: Figure 3 is a side view of the said strengthening or stiffening piece, and
Figure 4 is an edge view of the same.
The remaining Figures of the drawing are hereinafter referred to.
The strengthening or stiffening piece shown in Figures 1 to 4 consists of a vertical
plate or web a having a circular plate or flange b at each end thereof, which fits
tightly within the pole c. The arrows in Figure 2 indicate the directions in which
the telegraph wires usually extend from the post or pole.
I prefer to make the said strengthening or stiffening piece with a rib or projection b¹
on the underside of the lower flange b, corresponding in direction to the plate or
web a, so that the position of the said plate or web, after the stiffening piece has been
inserted, can be readily ascertained.
Figure 5 is a side view.
Figure 6 an edge view, and
Figure 7 a transverse section of a modified form of my stiffening piece having
intermediate plates or flanges 62 for preventing collapse of the pole. These flanges
and also the flanges b are strengthened by means of ribs b³.
of
Figure 8 shows, in section, a post or pole formed of a single tube provided with one
my stiffening pieces.
Figure 9 shows, in section, a post or pole formed of two tubes c, c', each of which is
provided with one of my stiffening pieces.
Figure 10 is a portion of Figure 9 drawn to an enlarged scale.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I wish it understood that I do
not claim generally or irrespectively of the improvements herein specified the use
of strengthening or stiffening pieces in tubular telegraph posts or poles, but I
claim :-
First. A post or pole formed of one or more tubes provided with the improved
strengthening or stiffening pieces, substantially as, and for the purpose, hereinbefore
described.
Second. A strengthening or stiffening piece constructed substantially as herein-
before described for the purpose specified.
Dated this 9th day of November 1887
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.