IM- PROVEMENTS IN SEWER VENTILATORS AND MAN-HOLE COVERS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Henry Robins at the
Office of the Commissioners of Patents on the 8th January 1879.
WILLIAM HENRY ROBINS, of City Chambers, 82, New St., Birmingham, in the
County of Warwick, Land and Engineering Surveyor and Estate Agent. "IM-
PROVEMENTS IN SEWER VENTILATORS AND MAN-HOLE COVERS."
This apparatus consists of three distinct pieces, which shall throughout this
Specification be distinguished as the grid, the frame, and the dirt box.
The grid consists of a strong casting of suitable shape which may be varied to
suit circumstances so long as the following particulars are adhered to, viz. :-
1st. The grid is provided with holes of size and shape convenient for lifting with
the hand the said grid from its seating in the frame, and which holes also form
apertures for ventilation.
2nd. The divisions between the said holes being arranged diametrically and
midway between each extremity of the grid thus materially strengthen it at the
weakest points.
3rd. The spaces between these divisions being provided with suitable pockets in
which pieces of hard wood are inserted to prevent the foot slipping when passing
over the grid.
4th. To facilitate the removal of these pieces for repairs or otherwise a hole is
provided in the bottom of each pocket, which hole passes through the casting so
that by inserting a suitable instrument in the said hole the pieces may be driven
out and new ones inserted in a short space of time and without injury to the grid.
The frame consists of a rectangular cast-iron plate provided with projecting
flanges of suitable form and section to receive the grid and dirt box, each of which
has an independent seating in the same.
The dirt box consists of a hollow casting curvilinear in all its sections in order to
facilitate the cleaning out of the same from time to time. Round the upper and
outer edge of this box a flange or projection is formed which fits into and upon a
suitable rest provided for its reception in the before mentioned frame. This box is
further provided with handles for the greater ease of lifting in and out of its seating,
and has around its sides a number of perforations through which the sewer gas
passes on its way to its outlet in the grid; the said holes also drain off any water
received into the dirt box through the outlet in the grid.
In cases where desirable an arrangement is provided within the dirt box for
carrying a tray or trays of suitable form for holding charcoal or other disenfectant,
through or over which the sewer gas must pass on its way to the outlets in the grid,
the disenfectant at the same time being protected from injury by wet.

page_text: Having now described the various individual parts of the said Invention, let it
be understood that the frame being first permanently fixed in its place over the
man-bole or ventilator, the dirt box is then inserted, resting on its own separate
seating in the said frame, and finally the grid is put on, also resting on its own
seating, which is altogether distinct from that of the dirt box; thus the crushing
action of a heavy load in passing over the grid is sustained and carried by the frame
without being transmitted to the moro fragile dirt box beneath it, whilst for
cleaning out all that is necessary is to remove first the grid and then the dirt box,
which effects a considerable saving of time as compared with most forms of man-
holes and ventilators now in use, and also prevents the grid getting fast in the frame
by corrosion, &c., &c., thus keeping the man-hole or lamp hole easy of access when
required.