IMPROVEMENTS IN ROTARY FANS FOR VENTILATING _ MINES AND OTHER SIMILAR PURPOSES."
Year: 1881

page_text: LETTERS PATENT to James Shepherd Davidson, Charles Richard Steele, and
James Lyon, all of Whitehaven, in the County of Cumberland, Engineers,
for an Invention of "IMPROVEMENTS IN ROTARY FANS FOR VENTILATING
_ MINES AND OTHER SIMILAR PURPOSES."
PROVISIONAL SPECIFICATION left by the said James Shepherd Davidson,
Charles Richard Steele, and James Lyon at the Office of the Commissioners
of Patents on the 27th January 1881.
JAMES SHEPHERD DAVIDSON, CHARLES RICHARD STEELE, and JAMES LYON,
all of Whitehaven, in the County of Cumberland, Engineers. "IMPROVEMENTS
IN ROTARY FANS FOR VENTILATING MINES AND OTHER SIMILAR PURPOSES."
Our Invention, which relates to improvements in rotary fans for ventilating or
exhausting air in mines and other similar purposes, has reference to that class of
rotary fans in which a current is produced in a direction at right angles to that of
the notion of the blades of the fan, and the Invention consists more particularly
in the peculiar formation of the blades of such fans and in their general arrange-
ment, as hereinafter described.
In carrying out our Invention the blades are contained within a circular casing,
and the shaft carrying the blades passes through the said casing, and is supported
by standards fixed at either side, the shaft being rotated by belting or by other
convenient means.
The blades are preferably four in number, and are fixed upon a boss mounted
upon the shaft, and are arranged thereon radially and at right angles to each other.
The blades are also arranged upon their boss at angle with the rotating shaft,
preferably at an angle of about 45 degrees, so that upon the blades being set in
motion the current is produced in a direction parallel with the rotating shaft, that.
is to say, at right angles to the line of motion of the blades.
The blades are formed of greater width towards their centre of motion than at
their extremities, so that they taper gradually from near the boss towards their
extremities. The leading edges of the blades are preferably curved, and project
forward from the line on which they are set on the boss in order that the blades
may act upon the air more effectively.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Shepherd Davidson, Charles Richard Steele, and James
Lyon in the Great Seal Patent Office on the 26th July 1881.
JAMES SHEPHERD DAVIDSON, CHARLES RICHARD STEELE, and. JAMES LYON,
all of Whitehaven, in the County of Cumberland, Engineers. "IMPROVEMENTS
IN ROTARY FANS FOR VENTILATING MINES AND OTHER SIMILAR PURPOSES."
Our said Invention, which relates to improvements in rotary fans for ventilating
mines or for forcing or exhausting air for other similar purposes, has reference to
that class of rotary fans in which a current is produced in a direction_at right
angles to that of the motion of the blades of the fan, and our said Invention
consists more particularly in the peculiar formation of the blades of such fans and
in their general arrangement, as hereinafter described.
In carrying out our Invention the blades are contained within a circular casing,
and the shaft carrying the blades passes through the said casing, and is supported
by standards or bearings fixed at both sides or ends, the shaft being rotated by
belting or by other convenient means.
The blades of the fan are preferably four in number, and are fixed upon a boss
mounted upon the shaft, and which are arranged radially thereon and at right
angles to each other. The blades are also arranged upon their boss at an angle
with the rotating shaft, preferably at an angle of about 45 degrees, so that upon
the blades being set in motion the current is produced in a direction parallel with
the rotating shaft, that is to say, at right angles to the line of motion of the
blades.
The blades are formed of greater width towards their centre of motion than at
their extremities, so that they taper gradually from near the boss towards their
extremities. The leading edges of the blades are preferably curved, and project
forward from the line on which they are set on the boss in order that the blades
may act upon the air more effectively.
And in order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figures 1 and 2 of the accompanying Drawing represent longitudinal and
transverse sectional elevations respectively of an air exhausting, blowing, or
ventilating machine, constructed and arranged according to our said Invention.
The fan consists of four blades A1, A2, A3, A4, each of which are portions of a
screw of suitable pitch and peculiar shape before mentioned in order to give the
maximum efficiency. The blades radiate to a common centre line, and are secured
at equal distances at right angles round the circumferences to a central boss B,
either by angle irons or other similar means. The blades are formed with greater
width towards their axis of rotation than at their extremities, and their leading
edges are preferably curved and project forward, as shewn in the Drawings. The
boss B is keyed on a shaft E running in two or more bearings on the top of
suitable standards or bearings F, F, which are carried and attached to a bed
plate G. The boss with its four blades is contained or enclosed in a casing C of
wrought or cast iron conveniently formed in two halves to allow of easy access,
and a suitable opening at both ends (the full diameter of fan), and either end may
be used as the air discharge or inlet according to the direction in which the fan is
caused to revolve. The casing C is suitably secured to a bed plate G. Motion
may be imparted to the fan through a pulley D on the shaft E, as shewn, or other
similar device driven by any convenient source of motive power.

page_text: Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be used or carried into
effect, we would observe in conclusion that what we consider to be novel and original,
and therefore claim as the Invention secured to us by the hereinbefore in part
recited Letters Patent is,-
The construction and arrangement of ventilating, exhausting, or forcing machine,
consisting of blades, arms, or vanes of tapering breadth, with peculiar pitch and
configuration, and contained within a suitable casing, so as when set in motion to
produce a blast or current of air at right angles to their path of rotation,
substantially as and for the purposes hereinbefore described and illustrated in the
accompanying Drawings.
In witness whereof, I, the said James Shepherd Davidson, on behalf of myself
and the said Charles Richard Steele and James Lyon, have to this our
Specification set my hand and seal, this Twenty sixth day of July, One
thousand eight hundred and eighty one.
JAMES SHEPHERD DAVIDSON. (L.S.)