IMPROVEMENTS IN THE CONSTRUCTION OF CENTRIFUGAL VENTILATORS OR FANS
Year: 1868

page_text: LETTERS PATENT to George Davies, of No. 1, Serle Street, Lincoln's
Inn, in the County of Middlesex, and No. 87, St. Vincent Street, in
the City of Glasgow, Civil Engineer and Patent Agent, for the
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF CENTRIFUGAL
VENTILATORS OR FANS."-A communication from abroad by Marc
Reichenbach and Samuel Golay, both of Paris, in the Empire of
France.
Sealed the 25th September 1868, and dated the 1st April 1868.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners of Patents, with his Petition,, on the.
1st April 1868.
זיי י
I, GEORGE DAVIES, of No. 1, Serle Street, Lincoln's Inn, in. the:
County of Middlesex, and No. 87, St. Vincent Street, in the City of
Glasgow, Civil Engineer and Patent Agent, do hereby declare the nature.
of the said Invention for "IMPROVEMENTS. IN. THE CONSTRUCTION OP. CEN-

page_text: TRIFUGAL VENTILATORS OR FANS," (a communication from abroad by Marc
Reichenbach and Samuel Golay, both of Paris, in the Empire of France,)
to be as follows:-
These improvements in the construction of centrifugal ventilators
consist,―
Firstly. In the addition to the circumference of the envelope or
casing of an annular chamber serving as a receptacle for the air drawn
to the centre of the apparatus and which is compressed by the rapid
movement of the wings or vanes. The casing of the ventilator is formed
of two shells so arranged as to allow of communication between the
interior thereof and the annular receptacle by a narrow annular opening.
The vanes of the ventilator are symmetrical and flat which allows of
their turning indifferently in either direction, they work in a space
the section of which presents a conical and curvilinear form analogous
to that of the blade of an "eraser;" the air chamber or receptacle
may be pierced with several orifices to conduct the compressed air to
the places where it is to be utilized.
Secondly. In the optional substitution for the vanes ordinarily
employed of a circular brush made of horsehair, whalebone, or metallic
wire. This brush is composed of a centre or core of wood mounted
on the ventilator shaft, and on the circumference of which are mounted
several rows of tufts which radiate from the centre to the circumference
and have sufficient sphere left between them towards the centre to
allow of the easy access of the air; these tufts expanding to the sides
of the apparatus prevent the air from being whirled against the same
and being uselessly lost. The application of this brush completely
avoids the noise which rotary ventilators or fans ordinarily make, and
allows of the obtainment of a complete hermeticity, consequently pre-
venting all loss of wind. The whole of these arrangements have for
object the diminution in a very considerable degree of the resistance
in such ventilators and consequently of the power necessary to drive

page_text: .
SPECIFICATION in pursuance of the. conditions of the Letters Patent,
filed by the said George Davies in the Great Seal Patent Office on
the 30th September 1868.
:
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of No. 1, Serle Street, Lincoln's Inn, in the County of Mid-
dlesex, and No. 87, St. Vincent Street, in the City of Glasgow, Civil
Engincer and Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of April, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Davies, Her special licence that I,
the said George Davies, my executors, administrators, and assigns, or
such others as I, the said George Davies, my 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 THE CONSTRUCTION OF
CENTRIFUGAL VENTILATORS OR FANS," (a communication to me from abroad
by Marc Reichenbach and Samuel Golay, both of Paris, in the
Empiro of France,) upon the condition (amongst others) that I, the
said George Davies, my executors or administrators, by an instru-
ment in writing under my, or their, or one of 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 I, the said George Davies, do hereby declare
the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by
the following statement in writing, reference being had to the accom-
nanving Sheet of Drawings, that is to say:-

page_text: These improvements in the construction of centrifugal ventilators
or fans consist, -
Firstly. In the addition to the circumference of the envelope or casing
of an annular chamber serving as a receptacle for the air drawn to
the centre of the apparatus, and which is compressed by the rapid
movement of wings or vanes. The casing of the ventilator is formed
of two shells so arranged as to allow of communication between the
interior thereof, and the annular receptacle by a narrow annular opening.
The vanes of the ventilator are symmetrical and flat which allows of
their turning indifferently in either direction, they work in a space
the section of which presents a conical and curvilinear form analagous
to that of the blade of an "eraser;" the air chamber or receptacle may
be pierced with several orifices to conduct the compressed air to the
place where it is to be utilized.
.
Secondly. In the optional substitution for the vanes ordinarily
employed of a circular brush made of horsehair, whalebone, or metallic
wire. This brush is composed of a centre or core of wood mounted
on the ventilator shaft, and on the circumference, of which are mounted
several rows of tufts which radiate from the centre to the circumference,
and have sufficient space left between them towards the centre to
allow of the easy access of the air; these tufts expanding to the sides
of the apparatus prevent the air from being whirled against the same
and being uselessly lost. The application of this brush completely
avoids the noise which rotary ventilators or fans ordinarily make and
allows of the obtainment of a complete hermeticity, consequently
preventing all loss of wind. The whole of these arrangements have
for object the diminution in a very considerable degree of the resistance
in such ventilators and consequently of the power necessary to drive
them.
Such being the nature and object of the said Invention for "Improve-
ments in the Construction of Centrifugal Ventilators or Fans," I
will now proceed to describe more in detail the manner in which
the same is to be or may be performed or carried into practical effect.
And in order that the same may be distinctly understood I have annexed
hereunto a Sheet of Drawings illustrative thereof, and have marked
the same with figures and letters of reference corresponding with those
in the following explanation thereof, that is to say:-

page_text: Figure 1 in the annexed Drawing is a vertical section of the improved
ventilator or fan having an annular air receiving chamber and several
air exits, the vanes being replaced by a circular brush.
Figure 2 is a corresponding transverse section; the shells a and a'
are united by screws and constitute the casing or envelope and the:
framing of the whole system, they also form the air chamber f, which;
communicates with the fan itself by the narrow space between the:
two shells; d are the orifices which give passage to the air drawn
in by the vanes (which are of a conical and curvilinear form as shown
by the red lines in Figure 2) or by the circular brush 6.) The air
chamber is provided with a certain number of short tubes f¹ (for.
the exit of the compressed air) which may communicate separately
with an equal number of different conduits, or may be united by
elbow pipes so as to direct the whole of the air into a single tube.
On the axis of the fan are keyed the sockets g, which serve to fix
the wooden nave which carries the tufts forming the brush 6; by means
of this arrangement the mounting of the apparatus is exceedingly
simple, and yet the brush is fixed to the axis i in a solid manner.
I would here remark that care. must be taken to leave sufficient.
space between the bases of the tufts which form the brush, in order.
to permit the air to penetrate into the centre of the apparatus and
flow into the annular space d, by all the interstices which the tufts
have between them in order to increase the power of the delivery
of the fan. The tufts also are caused to spread in contact with the
sides of the fan so that the air once put in motion cannot return and
whirl against the sides; this hermeticity which it is impossible to attain
with vanes which would rub against the faces of the apparatus, is
without any drawback in this arrangement, the bristles wearing
exactly in such a manner as to fit the form of the sides without any,
humming or noise resulting therefrom. The Inventors reserve the right
in this as well as in the ordinary forms of fan to vary the material
employed for forming the tufts of the brush.
Figure 4 represents the application of this system to another form
of fan a; the brushes 6 are mounted in a wooden nave c keyed on the
axis of the fan, care being taken that they touch (or nearly so) the
lateral walls of the fan. It is always essential that the tufts composing
the brush should be placed sufficiently far apart to allow of the

page_text: introduction of the air towards the centre of the apparatus so as to fill
the open annular space d, and run along the bristles between which
it becomes imprisoned.
Figure 3 shows the application of this system of brush to a fan
of large dimensions in which the vanes ordinarily employed are
also replaced by brushes 6; in this arrangement the brushes are
mounted on circlets or rings e, placed sufficiently apart to allow of
the air passing between the bristles which form the brushes and
entering the annular space d, which communicates with the air exit f.
It will however be understood that the different arrangement shown
for the mounting of the brushes may be varied in any way, and that
the brushes may be made in any substance, animal bair, vegetable
fibre, whalebone, metallic wire, and so forth, since the Invention
consists essentially in the employment of any kind of brushes instead
of the vanes or pallets usually employed in fans for communicating
to the air the desired velocity.
Having now described the nature and object of the said Invention
for "Improvements in the Construction of Centrifugal Ventilators or
Fans," together with the manner in which the same is to be or may
be performed or carried into practical effect, I would remark in con-
clusion that I claim as the Invention communicated to me by the
above-named Marc Reichenbach and Samuel Golay),-
Firstly. The adaptation to centrifugal fans or ventilators of a circular
and annular air chamber from which branches a certain number of
tubes to conduct the air to any place where it is to be utilized.
Secondly. The employment of a section of a conical and curvilinear
form for the air chamber in which the vanes rotate, this chamber
communicating with the air chamber or receptacle by a narrow annular
opening.
Thirdly. The employment of brushes of any kind as a substitute 3
for the vanes or pallets of fans and for giving to the air the required
velocity.
Fourthly. The particular arrangements shown for mounting the
said brushes on the axes of the fans. The object of these brushes is
to dispense with the usual humming or noise, and to obtain a complete 3
hermeticity which augments the useful effect of such apparatus.

page_text: All these arrangements combined allow of a velocity of 3,500 to 4,000
revolutions being given to the apparatus without producing any
wearing of the parts, and at the expenditure of very little motive power.
In witness whereof, I, the said George Davies, have hereunto set
my hand and seal, this Thirtieth day of September, in the year
of our Lord One thousand eight hundred and sixty-eight.