IMPROVEMENTS IN WOOD PAVING
Year: 1878

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company,
Patent Solicitors, at Frankfort on the Main, in the Empire of Germany, for
the Invention of "IMPROVEMENTS IN WOOD PAVING." A communication from
Christian Graff, of Stuttgart, in the Empire of Germany.
Sealed the 20th June 1879, and dated the 28th December 1878.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 28th December 1878.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort on the Main, in the Empire of Germany. "IMPROVEMENTS IN WOOD
PAVING." [A communication from Christian Graff, of Stuttgart, in the Empire
of Germany.]
This Invention consists in laying a foundation of concrete, which, when rolled
flat and surfaced over, receives a covering of well tarred roof felting or mastic, upon
which is placed wood blocks, which are cut about four centimeters thick, and
connected together by bands of rolled iron in such a manner that they can be
finished in the factory, and only require adjusting in the street or other place where
the paving is laid. Wood pavements so constructed can be taken up and laid down
more casily than any other.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frank Wirth in the Great Seal Patent Office on the 25th Juno
1879.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at Frank-
fort on the Main, in the Empire of Germany. " IMPROVEMENTS IN WOOD
PAVING." A communication from Christian Graff, of Stuttgart, in the Empire
of Germany.
The Invention consists chiefly in constructing the wooden pavement with an
iron net or frame, and in forming a number of blocks into sections or plates
before they are laid on the road, as will be more clearly understood from the
accompanying Drawings. Fig. 1 shows a cross section of a street pavement, where
R and R are the border stones which separate the foot paths from the main road;
E, E¹, the underground upon which the concrete foundation B, B¹ is laid. The
strength of the latter depends upon the greater or smaller traffic which it has to
serve, and other known circumstances, and should be such as to maintain the shape
of the road section invariable. The wooden pavement is, however, not directly
placed upon the concrete foundation, but upon a layer of carton-pierre or similar
substance which affords a more equal and fitting support for the base of the
pavement blocks. A block of this wood pavement is illustrated in elevation, and
in a larger scale by Fig. 4; it has approximately the shape of a prism with
quadratic base, the sides measuring about 4 inches, and the height 2 inches. The
sides are provided with grooves for receiving the bars of the iron net, those
opposite and parallel with each other being equal. The front groove (equal to that
at the back) is designated with e, f, and the side grooves with g and h. Fig. 5 is a
horizontal section through line o, p, of Fig. 4, and a plan of the contiguous net
bars of the latter there are two classes, the long continuous bars l, m, l, m¹, and
the short transverse bars i, k, i, k, as further illustrated in Figs. 6 and 7; l, m, is
a Tiron, and i, k, a rectangular bar slotted at both ends for receiving the flanges
of the iron, as shown in Fig. 5; Fig. 2 shows a piece of a paved road in plan,
where again l, m, l', m¹, indicate the position of the continuous bars, and i, k, i', k¹.
the position of the cross bars. The quadrangle a, b, c, d, represents a section of
wood pavement of about 10-11, square feet, which can be made ready at the works
to be transported upon the road. In order to facilitate the transport of such large
sections of wood pavement strips of sheet iron n, n', Fig. 3, may be nailed on the
circumference of a section, so as to enclose the latter and form a compact piece.
The various sections may be connected in the following manner:-The sheets or
sections coming from the yard are laid so as to leave between them some clearance,
which is closed by strips of flat iron S, Fig. 3, and finally the connection is com-
pleted by a suitable number of double nails N. If one or more sections are to be
removed from the road this can easily be done after taking out the double nails N
and the strips S'; any kind of wood may be used for this pavement.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand
and seal, this Twenty first day of June, A.D. 1879.
FRANK WIRTH. (L.S.)