IMPROVEMENTS IN Apparatus FOR VENTILATING MINES
Year: 1875

page_text: LETTERS PATENT to William Knott, of Wigan, in the County of
Lancaster, Ironfounder, and Thomas Rudd, of Blackrod, near
Wigan aforesaid, Engineer, for the Invention of "IMPROVEMENTS IN
Apparatus FOR VENTILATING MINES."
Sealed the 31st August 1875, and dated the 12th March 1875.
PROVISIONAL SPECIFICATION left by the said William Knott and
Thomas Rudd at the Office of tho Commissioners of Patents, with
their Petition, on the 12th March 1875.
We, WILLIAM KNOTT, of Wigan, in the County of Lancaster, Iron-
founder, and THOMAS RUDD, of Blackrod, near Wigan aforesaid,
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR VENTILATING MINES," to be as follows:-
In ventilating mines it is customary to employ very large fans to
produce the requisite currents of air in the shafts and workings, and our
Invention consists in placing the wings of such fans at an angle to the
axis instead of parallel thereto, as now usual; this increases the currents
and reduces the power for driving.

page_text: Another part of our Invention consists in making the casing of such
fans of cast or wrought iron instead of brickwork, thereby greatly reducing
the cost of construction; also in varying the discharge orifice by means
of a pair of plates hinged together and moved to and fro in the flue by
rack and pinion or other equivalents; also in the use of one or more
stationary plates that are put into the flue at various distances from the
sides to reduce the discharge orifice.
Another part of our Invention consists in driving the said fans by
means of steam engines set diagonally on the frame supporting the ſan
shaft, and connected to a crank on the fan shaft, so that when one
engine is out of repair the other can be instantly coupled to the crank
shaft.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said William Knott and Thomas Rudd in the Great
Scal Patent Office on the 11th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, WILLIAM
KNOTT, of Wigan, in the County of Lancaster, Ironfounder, and
THOMAS RUDD, of Blackrod, near Wigan aforesaid, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of March, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
cighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Knott and Thomas Rudd, Her
special licence that we, tho said William Knott and Thomas Rudd, our
executors, administrators, and assigns, or such others as we, the said
William Knott and Thomas Rudd, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for " IMPROVEMENTS IN APPARATUS FOR VENTILATING
MINES," upon the condition (amongst others) that we, the said William
Knott and Thomas Rudd, our exccutors or administrators, by an instru-

page_text: ment in writing under our, or their, or one of our or their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that we, the said William Knott and Thomas Rudd
do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say) :—
In ventilating mines it is customary to employ very large fans to
produce the requisite currents of air in the shafts and workings, and our
Invention consists in placing the vanes or wings of such fans at an angle
to the axis instead of parallel thereto, as now usual; this increases the
currents and reduces the power for driving.
Another part of our Invention consists in making the casing of such
fans of cast or wrought iron instead of brickwork, thereby greatly
reducing the cost of construction; also in varying the discharge orifico
by means of a pair of plates hinged together and moved to and fro in
the flue by rack and pinion or other equivalents.
Another part of our Invention consists in driving the said fans by
means of steam engines set diagonally on the frames supporting the fan
shaft, and connected to a crank on the fan shaft.
And in order that our Invention may be fully understood, and
readily carried into operation, we will proceed to describe the accom-
panying Sheet of Drawings, reference being had to the figures and
letters marked thereon.
Fig. 1 is an elevation, and Fig. 2 a transverse section of a ventilating
fan constructed according to our Invention. a is the shaft or axle of
the fan, and the vanes or wings, which instead of being parallel to the
axis, as now customary, we place obliquely, as shown best in Fig. 2.
Each vane is secured to the centre bosses c by means of three or other
convenient number of arms & made of angle or other section of iron.
The object of thus placing the blades obliquely to the axis is to increase
the current of air and to reduce the power required for driving. The

page_text: outer edges of the vanes are connected together by one or more annular
bands.
The casing of the fan consists of the sides e, which are made by
preference of cast-iron segments bolted together, the two lowest
segments being bolted on the frames & supporting the fan, as will be
described hereafter, and the segments e are connected by the plates f
forming the circumference of the casing. These plates are bolted to
the sides e. The casing may, however, be of wrought iron if preferred.
The interior of the fan is in communication with the mine to be
ventilated by means of the flue g opening into the centre of the fan,
and the vitiated air is blown off through the discharge pipe h; the
discharge orifice being parallel to and of the full width of the fan. The
internal area of the discharge pipe / may be varied by means of a pair
of plates hinged together and moved to and fro so as to cause them to
expand or collapse, and thus reduce or increase the orifice of the
discharge pipe by a rack and pinion, or other equivalents.
The axle a is supported in pedestals bolted to the frames %, which are
fixed to the foundation plates 7, and theso plates are bolted down on the
stone and brick foundations m. The steam engines by which the fan is
driven are secured to the diagonal sides of the frame k, and the connect-
ing rods of both steam engines are jointed to the crank pin a¹ fixed in
the disc a², keyed on the axle of the fan; by this arrangement the casing
of the fan, the pedestals of the fan shaft, and the steam engines for
driving the fan are all secured to the frames k, thereby increasing the
strength of the whole structure.
Having thus stated the nature of our Invention, and described a
convenient manner of performing the same, we wish it to be understood
that we do not intend to limit ourselves to the details given, as the same
may be varied or modified according to the diameter of the fan, we
claim,―
First. Placing the vanes or wings of fans for ventilating mines
obliquely to the axis, for the purposes described.
Secondly. Making the casings of ventilating fans of cast or wrought
iron, as shewn and described.
Thirdly. Varying the orifice in the discharge flue by means of a pair
of plates hinged together, as described.

page_text: And, lastly. Supporting the casing of the fan, the pedestals of the
fan shaft, and the driving engines on the same frames as shewn and
described.
In witness whercof, I, the said William Knott, for myself and on
behalf of the said Thomas Rudd, have hereto set my hand and
seal, this Fourth day of September One thousand eight hundred
and seventy-five.