IMPROVEMENTS IN MACHINERY FOR RAISING OR PROPELLING ELASTIC AND NON-ELASTIC FLUIDS."
Year: 1853

page_text: LETTERS PATENT to Charles Augustus Holm, of 21, Cecil Street,
in the County of Middlesex, Civil Engineer, for the Invention of
"IMPROVEMENTS IN MACHINERY FOR RAISING OR PROPELLING ELASTIC
AND NON-ELASTIC FLUIDS."
PROVISIONAL SPECIFICATION left by the said Charles Augustus
Holm at the Office of the Commissioners of Patents, with his
Petition, on the 6th October 1853..
I, CHARLES AUGUSTUS HOLM, of 21, Cecil Street, in the County. of
Middlesex, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MACHINERY FOR RAISING OR-PROPELLING
ELASTIC AND NON-ELASTIC FLUIDS" to be as follows:-
The Invention consists in the application of a screw or portions of a
screw to the entrance orifice of centrifugal fans or pumps, the centri-
fugal arms of which are formed to the extent of the radius of the
entering orifice of the apparatus with a pitch corresponding with the
velocity of the entering fluid, and then such pitch is increased by a
portion of a circle until the arms form tangents to such circle, by which
the current of fluid on entering the orifice of the centrifugal fan or
pump is gradually changed from a linear motion into that of a rotatory

page_text: power
motion without any sudden striking against the revolving arms, whereby
is saved, and the channels are curved, and agree in dimensions
with the encrease of the centrifugal velocity of the moving fluid through
the wheel, thus avoiding any unnatural expansion or contraction of the
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Augustus. Holm in the Great Seal Patent
Office on the 6th April 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
CHARLES AUGUSTUS HOLM, of 21, Cecil Street, in the County of Mid-
dlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of October, in the year
of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Charles Augustus Holm,
Her special licence that I, the said Charles Augustus Holin, my exc-
cutors, administrators, and assigns, or such others as I, the said Charles
Augustus Holm, 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 law-
fully 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 MACHINERY FOR RAISING AND PRO-
PELLING ELASTIC AND NON-ELASTIC FLUIDS," upon the condition (amongst
others) that I, the said Charles Augustus Holm, by an instrument in
writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
sanie 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 Charles Augustus Holm, do
hereby declare the nature of the said Invention, and in what manner

page_text: the same is to be. performed, to be particularly described and ascer
tained in and by the following statement thereof (that is to say):;.
The Invention consists in the application of a screw or portions of a
screw to the entering orifice of centrifugal fans, wheels, or pumps, the
generatrix of which screw forms part of, the centrifugal arms to the
extent only of the radius of the entering orifice; and the directrix of*
such screw or portions of screw is so adjusted that the pitch at the
entrance shall correspond with the velocity of the entering fluid; and
afterward the directrix of the pitch shall increase by a portion of a
circle, until the centrifugal arms form tangents to such circle; or, in
other words, that the movement of the current shall, in entering the
orifice of the centrifugal fan wheel or pump, be gradually changed from
its linear motion into that of a rotatory without any sudden striking
against the revolving arms, whereby power would be lost. The chan-
nels for the passage of the fluid are curved, and have such forms and
proportions of areas that they shall contract at any part of the wheel's
radius in such proportions as will correspond to the increase of the
centrifugal velocity of the moving fluid in its passage through the
wheel, and thus avoid any unnatural expansion, retardation, or contrac-
tion of such fluid. The introduction of centrifugal pumps for the
purpose of raising fluids has been limited on account of the great waste
of motive power, and the object of this Invention is to remove the
difficulty which has been the cause of this loss of power. The loss of
power in the centrifugal pump has arisen from two, and sometimes
three causes; first, in some case, in the use of straight arms instead
of curved; secondly, in allowing the fluid, in entering the central
passage of the pump, to strike against the centrifugal arms or vanes;
thirdly, in allowing the fluid to contract, expand, or retard its velocity
by not having proper form and proportions of the delivery channels.
DESCRIPTION OF THE DRAWING.
Figures 1, 2, and 3, are sections of the wheel through the plane o
rotation under different proportions of construction. Figures 4, 5, and
hool through the axis of the central passage

page_text: The wheel is composed of a hollow disc having a number of curved
arms and vanes. The fluid to be raised or compressed enters at the
central orifices A, and is expelled at the circumference at B, by the
revolutions of the disc. C, C, C, are the curved vanes; and D, D, D,
are curved centrifugal arms, being portions of a cylinder of nearly one
half of the circumference, and placed between the centre of the wheel
and its circumference, so that such arms shall be nearly tangents to the
circumference of the wheel. E, E, E, are portions of a screw having a
curved generatrix of the same radius as the radius of the centrifugal
arms D. The screw blades E, are united to the centrifugal arm D, by a
screw of an increasing pitch, or curved directrix, which being a portion
of a circle in such a manner that this directrix forms tangents at the
same time to the screw blade E, and the centrifugal: arms D; this
curve or increase of the pitch is shown at F, by the shading of the
arins; the power for working the wheel is-comniunicated to the central
shaft G. In these different examples of construction the central
passage or ratio of diameter to that of the wheel are of different
dimensions, in order to suit different heights of elevation or com-
pression; the small ratio of diameter of the central passage will
answer for higher lifts, and the larger one for low lifts; and on
the ratio of diameter of the central passage to the diameter of the
wheel depends the proportions of the delivery passage, and which pas-
sages should also be composed of curved surfaces, independent of the
curved arms. To determine the form of this curved passage I divide
the distance between the circumference of the central orifice and the
circumference of the wheel into a given number of parts, represented
by the-lines- H; I, K, L, M, N; and on the line H, I find the height
of a cylinder that would, with an equal diaineter as the central passage,
give me the same area at its circumference as the said central passage,
and I represent this height of cylinder by a circle. Now in order to
find the proper height at any other point of the wheel's radius I repre-
sent such heights by a circle, and the diameter of such circle multiplied
by the square of the radius from the centre of the shaft 'to the centre
of the circles respectively should in all cases be equal to the diameter
of the circle on the line H, multiplied by the square of the radius

page_text: from the centre of the wheel to the centre of the circle on the line H,
or; in other words, the area of discharge at any point of the wheel's
radius from the centre. shall diminish inversely as the length of the
radius of the circumferential orifice.
Having thus determined the diameter of the different heights repre-
sented by the circles on the lines I, K, L, M, N; I draw curves that
shall form tangents to these different circles; and these curves will be.
the proper form for passages of the delivery channels of the disc. The.
pitch of the screw is in this example 1 times the diameter of the
central orifice; the wheel is to be mounted in a suitable casing "with"
suction pipes according to the different purposes for which it might be
wanted; and I have not thought necessary to shew these parts, as they
must of course be of different forms according to circumstances. If:
the wheel be used for raising water, and entirely immersed, the velocity.
of the circumference of the central passage should not exceed forty-
four feet per second; and the height to which water could be elevated
would be equal to three fourths of the height due to the velocity of the
circumference of the wheel. If the wheel has to lift the water by suction
the pitch of the screw must be less, so as not to feed the wheel faster than
the velocity of the rising fluid would allow. In case the height of ele-
vation should be less than three fourths of the height due to the velocity
of the circumference of the wheel the pitch of the screw must be
more than 1 times the diameter, so as to correspond with the velocity
of the fluid in the central passage. Should higher elevations of the
fluid be required than could be accomplished by these examples of con-
struction, wheels with smaller central passages may be constructed, or
the wheel may be made so as to have only a portion of the circum-
ference open, in which case it would resemble the curved arms of a
Barker's mill inclosed in a disc, and fitted with a screw in the central
orifice, as described, or several of the wheels shown in Figures 1, and 4,
may be mounted in a suitable casing one above the other, and worked
by the same shaft, or otherwise arranged in such manner that the fluid
raised by the first wheel shall be raised still further by the second, and
still further by a third, etc. etc., and in which case any amount of eleva-
tion or compression may be obtained. In raising other fluids than
.

page_text: water the velocity of the central passage and the pitch of the screw is
to be regulated according to the velocity that would be due to tlie
density of the fluid to be raised or compressed; the shaft of the wheel
could also be used in a horizontal position, and fitted with one or
several wheels, elevating or compressing fluids, either separately or com-
bined, to the same height, or to different heights. The wheel above
described may also be used as a motive power, and worked by the fluid
entering on the screw at the central orifice of the wheel.
What I claim as my Invention is, the application of a screw in com-
bination with curved arins, for the purpose of raising or propelling
clastic and non-elastic fluids, and also the application of curved sur-
faces to the wheel or disc, for the purpose of preventing contraction,
retardation, or expansion of the fluid in its passage through the wheel
as above described.
In witness whereof, I, the said Charles Augustus Holm, have
hereunto set my hand and seal, this First day of April, in the
year of our Lord One thousand eight hundred and fifty-four.
Witness,
GEO. PITT,
I
4, Old Square.
C. A. HOLM. (L.S.)