IMPROVE- MENTS IN THE CONSTRUCTION OF ROTARY FANS
Year: 1869

page_text: LETTERS PATENT to Edward William Voco and John Voce, both of
Salford, in the County of Lancaster, for the Invention of "IMPROVE-
MENTS IN THE CONSTRUCTION OF ROTARY FANS."
Scaled the 2nd July 1869, and datel the 5th January 1809.
PROVISIONAL SPECIFICATION left by the said Edward William Voce
and John Voce at the Office of the Commissioners of Patents, with
their Petition, on the 5th January 1809.
We, EDWARD WILLIAM VOCE and JOHN Voon, both of Salford, in
the County of Lancaster, do horoby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF ROTARY FANS," to be
as follows:-
This Invention relates to the construction of rotary fans such as are
used for the production of currents of air for ventilation and for various
manufacturing purposes, and has for its object the increase of the

page_text: amount of blast produced by a fan of given diameter without any
increase of the power required to drive the same.
The improvements consist principally in providing the casing or shell
which surrounds the fan with two or more vents or discharge openings
(in lieu of one only as commonly employed) and in increasing the
diameter of the central or inlet openings in a corresponding degree.
In fans as usually constructed with (say) three vanes and only one
vent or discharge opening, the air inclosed between each two vanes is
carried round more than two-thirds of the interior of the casing usclessly
before it is discharged at the vent, whereas by making three vents in the
casing the air between each two vanes is discharged immediately, and
consequently about three times the volume of air may be impelled by
a fan of the same diameter. In order to compensate for the rapidity
with which the air is discharged and to provent "wire drawing," we
increase the diameter of the two central or inlet openings in a corre-
sponding ratio, so that their united area is somewhat in excess of the
united area of the three vents or discharge openings.
It will be found that these improvements in the construction of fans
will effect a considerable increase of the amount of blast produced, and
will also allow of the fan being driven at a much higher.velocity without
increasing in a corresponding degree the amount of power required to
drive the same.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward William Voce and John Voce in the Great
Seal Patent Office on the 3rd July 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, EDWARD
WILLIAM VOCE and JOHN VOOE, both of Salford, in the County of
Lancaster, send greeting.
2
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of January, in the year of 3
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of .Her. reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Edward William Voce and John Voce,

page_text: Her special licence that we, the said Edward William Voco and Johu
Voce, our executors, administrators, and assigns, or such others as we, the
said Edward William Voce and John Voce, 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 THE CONSTRUCTION
OP ROTARY FANS," upon the condition (amongst others) that we, the said
Edward William Voce and John Voce, our executors or administrators,
by an instrument in writing under our, or their, or one of their hands
and scals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the samo to be filed in the Great Scal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that we, the said Edward William. Voce and John
Voce, 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 :-
This Invention relates to the construction of rotary fans such as aru
used for the production of currents of air for ventilation and for various
manufacturing purposes, and has for its object the increase of the
amount of blast produced.
The improvements consist principally in providing the casing or shell
which surrounds the fan with two or more vents or dischargo openings
(in lieu of one only as commonly employed) and in increasing the
diameter of the central or inlet openings in a corresponding degree.
In fans as usually constructed with (say) three vanes and only one
vent or discharge opening much air inclosed between each two vanes is
carried round more than two-thirds of the interior of the casing uselessly
before it is discharged at the vent, whereas by making three vents in the
casing the wind raised between each two vanes is discharged imme.
diately, and consequently about three times the volume of air may be
propelled by a fan of the same diameter. In order to compensate for
the rapidity with which the air is discharged and to provent "wire

page_text: drawing," I increase the diameter of the central or inlet openings in a
corresponding ratio, so that their united area is somewhat in excess of
the united area of the three vents or discharge openings.
It will be found that these improvements in the construction of fans
will effect a considerable increase of the amount of blast produced, and 5
will also allow of the fan being driven at a much higher velocity without
increasing in a corresponding degree the amount of power required to
drive the same.
Having thus particularly described the nature of our said Invention,
we now proceed to particularly describe and ascertain in what manner 1
the said Invention is to be performed or put in operation, which we shall
do by reference to the Drawings accompanying this Specification by the
aid of the letters and figures marked thereon and herein referred to, that
A denotes the case; B denotes the fan or vanes; O, the openings in
the sides of the case provided for the inlet of the wind; O*, the axis of
the fan; D, D, D, the vents or discharge openings for the wind. The
dotted lines show how ducts or passages may be applied to the vents or
discharge openings so as to collect the wind power from all the vents or
discharge openings and convey it all to one spot; but instead of the
whole of the wind power being thus collected and delivered in one body
it may, as aforesaid, be conveyed away direct from each vent or
discharge opening, or any two or any number may be connected together
according as convenience may dictate; it being always understood that
although the Drawings show three vents or discharge openings, any
convenient number of vents or discharge openings may be adopted.
Having now particularly described and ascertained the nature and
object of our said Invention, and in what manner the same may be
performed or carried into practical effect, we hereby declare that we
claim, the Invention of the horcin-before described "Improvements in
the Construction of Rotary Fans," in which two or more outlets for the
wind power raised are provided, it being understood that we do not
claim the mere details of construction shown by the Drawings, nor do

page_text: wo limit ourselves to the use thereof, as the same may be varied as may
be deemed requisite.
In witness whereof, we, the said Edward William Voce and John
Voce, have hereunto set our hands and seals, this Twenty-fifth
day of Juno, in the year of our Lord One thousand eight hundred
and sixty-nine.
Witness,
THOMAS ARCHER.
E. W. VOCE. (L.B.)'
J. VOCE.
(L.B.)