Year: 1888

page_text: Date of Application, 31st Jan., 1888
Complete Left, 28th Mar., 1888
Complete Accepted, 4th May, 1888
I, LADISLAV VOJÁČEK, of Smichov, Bohemia, in the Empire of Austria, Engineer,
do hereby declare the nature of my said invention to be as follows :-
My invention relates to the description of pumps and ventilators for which I have
obtained Letters Patent dated October 27th 1885, No. 12,886, and the object of my
present invention is to effect improvements in such pumps and ventilators.
In the above recited Letters Patent, the water or air (herein after referred to as the
"fluid") flows out in spiral curves or helices from the tubes of such pumps or
ventilators (herein after called "pumps "). The particles of fluid proceed in such a
manner as to form a hollow cylinder, concentric with the axis of rotation; each particle
of fluid being caused to ascend spirally on the inner face of the tube.
My present invention consists in closing the fixed casing with a fluid tight cover,
perpendicular to the axis of rotation. To this cover I fit one or more tube or tubes
near the periphery, so as to receive the vortex moving fluid and direct it upwards or
onwards. These tubes are so inclined and curved as to receive the vortex moving fluid
in such a manner as to carry the fluid onward, without materially checking its vortex
velocity or centrifugal force. The fluid thus passes through tubes forming spiral
curves, and its motion is continued to the desired height or distance.
In constructing vertical pumps having two or more tubes, 1 support the spindle or
shaft by means of provisions cast upon or attached to such tubes, the shaft carrying
adjustable driving pulleys for actuating the same.
In some cases the pumps are submerged, and the spindle or shaft is carried through
a plate, either above or below the turbine or centrifugal pump.
I also construct my improved pumps to work with the spindle or shaft placed in a
horizontal or any other required position. In all cases the spiral tubes lead the fluid
first in the direction of the axis of rotation, and then carry the same into any reservoir,
or directly to its place of destination.
In ventilators so formed I am able to obtain a much higher pressure of air than with
ordinary fans.

page_text: Improvements in Centrifugal Pumps and Ventilators.
I, LADISLAV VOJÁCEK, of Smichov, Bohemia, in the Empire of Austria, Engineer,
do hereby declare the nature of my said invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement
My invention relates to improvements in centrifugal pumps and ventilators, with
pump wheels, the blades and passages of which are so formed as to throw out the fluid
in the axial direction, as described in the Specification of Letters Patent granted to me
dated 27th October 1885, No. 12,886.
In the pumps and ventilators referred to, the wheels are enclosed in a fixed
casing, and the fluid is carried into a fixed cylinder or tube, the axis of
which is identical with the axis of rotation. The fluid, after leaving the wheel,
proceeds in a thin layer in the tube, and forms a hollow concentric cylinder. Each
molecule describes a helicoidal curve. The inclination of the curves relatively to the
axis, depends on the form of the wheel and blades; on the velocity of rotation, and
on the difference of pressures. But in any case, this inclination (or the pitch) is a very
small one, and constantly decreases, owing to the friction and motion of the liquids.
It soon arrives at the so-called limiting angle of friction, when the limit of pumping
effect is reached. The tube fills itself with liquid, which merely revolves without
producing the desired effect.
For this reason the useful effect of such pumps is small, and they can be used only
for low heights of delivery. They are also useless for purposes of suction, the reason
of which is as follows:-
The centrifugal force being considerable, the stream of fluid, where it leaves the
wheel, is a very thin one, leaving a considerable part of the tube empty. This
becomes filled with air, which enters from an opposite direction. This air prevents
the action of suction being effectual in a centrifugal pump, and also renders any
considerable pressure impossible in á ventilator. To avoid this effect of the air, this
part of the pump or ventilator must therefore be made air tight.
On changing the direction of the helicoidal curves in the tubes by the insertion of
fixed directing blades directly behind the wheel, the blades receive the fluid from the
wheel, for the purpose of guiding it in an axial direction. But the fluid enters
between the blades from a direction which is nearly perpendicular to the axis of
-rotation, and-no-free-passage-is-left-for-its-entrance.-Besides-which--the-blades--being-
short and curving vertically, the fluid is diverted towards the axis of rotation, which
causes a considerable loss of effect, and the object is not attained. The fluid leaves
such directing blades weakened in motive force and still having the inclination to
revolve in helicoidal curves, nearly perpendicular to the axis of rotation.

page_text: Now the object of my invention is to avoid these inconveniences, for which purpose
I enclose the case, in which the fan wheel revolves, with a fixed and airtight cover.
From this cover in order to receive the thin cylindrical stream of fluid as it issues
from the wheel, I fix one or more helicoidal tube or tubes. These tubes leave the
cover in such a manner as to direct the motion of the issuing fluid; the helicoidal
axes of the tubes gradually changing their inclination relatively to the axis of rotation
of the wheel.
This inclination gradually decreases until all the axes are parallel. If the sectional
areas of the tubes accord with correct calculation the fluid will entirely fill them, and
it will flow in helicoidal curves of a great pitch. In this manner very little change of
velocity, and only a successive one of direction is obtained, and no objectionable
current of air is admitted into the wheel of the pump or ventilator.
The blades are constructed so that anything which comes between them must be
thrown outwards the mouth of the wheel closing the space between the wheel
and its fixed casing. It is evident that this pump will draw better than any
other pump of this class hitherto known. For the same reason, and from the
use of the helicoidal tubes, I obtain with my ventilators a pressure of several
atmospheres, which it has been impossible to obtain with any ventilator of this class
hitherto known.
And in order that my said invention may be particularly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1 is a vertical section and elevation of a submerged vertical pump, with two
helicoidal tubes, the driving pulley being above.
Fig. 2 is a horizontal plan of the pump, the distance of the helicoidal tubes from
the axis of rotation being constant.
Figs. 3 and 4 are views of a modification of that shewn in Figs. 1 and 2, in which
the length of the helicoidal tubes froin the axis of rotation are increased, to meet the
increased distance apart of the vertical tubes.
Fig. 5 is a section through the axes of the helicoidal tubes shewn in fig. 2, projected
as a plane.
Fig. 6 is a vertical section and elevation of a suction pump; with three helicoidal
tubes, the pump being driven by a crank.
Fig. 7 shows the disposition of the helicoidal tubes m
direction.
np in a horizontal
Fig. 8 shows an application of the principle of helicoidal tubes with axial pump
wheels, to a horizontal centrifugal pump, in vertical elevation and section.
Fig. 9 is an elevation, partly in section, of a ventilator with two helicoidal tubes.
Fig. 10 is an elevation, partly in section, shewing the method of supporting the
shaft shown in Fig. 1.
Fig. 11 is a horizontal plan, partly in section of Fig. 10.
Fig. 12 illustrates an arrangement of wheels and pulleys for driving a centrifugal
pump by manual power.
a is the pump wheel (or ventilator wheel), a a is the shaft. b is the fixed casing in
which the wheel a revolves. c is the cover bolted to the casing, to exclude the air, the
cover being formed with passages leading to the helicoidal tubes.
The fluid or air enters the wheel a near its centre, and is discharged therefrom into
the tubes 1, 2, 3. The tubes gradually change the direction of the stream into the
direction of the axis of rotation xx.
The helicoidal tubes 1, 2, 3 are formed as indicated in figs. 3, 4, 6 and 7. If the
tubes are so formed that the distance of their axes from the axis of rotation az is
constant, the horizontal projection of those axes occur in the same circle. This case is
represented in figs. 1, 2 and 5.
These pumps can be used as submerged vertical pumps (see figs. 1 to 4) or as
vertical suction pumps (fig. 6) or as horizontal pumps (fig. 8) and the figures given
in the accompanying drawings shew only a few examples of many possible adaptations,

page_text: which may vary in each particular case. I sometimes modify the arrangement shewn
in Fig. 3 by fitting a turbine below the pump, thereby driving the shaft x directly;
the shaft passing through a stuffing box.
The arrangement shewn in fig. 1, with two tubes m n, near together, may be preferably
used when the shaft is long, in which case it can be supported by bearings as
represented by figs. 10 and 11. These bearings are provided wherever required and
formed with the tubes m n. The two parts of the plate, y and z (fig. 11) are bolted.
together, thus forming a horizontal base plate, upon which the bearings are mounted
in a box t. This box is also formed in two parts, united by two horizontal bolts u u,
and it can be adjusted in a horizontal direction by means of the bolts vv.
The arrangement of a ventilator, of which fig. 9 is an example, may also vary in
many ways; the essential feature of my invention consisting of the helicoidal tubes
upon the cover e of the casing b, and of a wheel with axial passages, as illustrated in
the drawings.
My improved centrifugal pumps and ventilators require less speed than ordinary
centrifugal pumps, and ventilators, for the same amount of work, in the ratio of
about 7 to 10.
The speed is of course very high, and the movement of the pump wheel must be
uniform, especially if the height of suction and delivery is considerable, owing to the.
mass of fluid in motion, which, in the contrary case, must change its velocity with
each change of speed of rotation.
It has hitherto been found practically impossible to construct centrifugal pumps
which were suitable for manual driving, although this would sometimes be of great
value. With my pumps I sometimes use the arrangement illustrated in fig. 12.
c is intended to indicate the axis of rotation of the pump, with two driving
pulleys d and d¹. I arrange two platforms w and w¹. Each of these carry a fixed
driving pulley and f, and the pullies e and e¹ (or several pullies as arranged) for
carrying the belt or cord. This belt is applied as shewn on the drawing, passing
from e to d, from d to f, from to f¹, from 1 to d, from d¹ to e¹ and from e' again
to e. It is evident that in turning for f¹ or both of these pulleys by manual power
the pump will rotate also; its velocity will increase in the ratio of the .diameters
off and to d and d¹ both ratios being equal.
The pulley for f may be turned with greater speed by means of toothed wheels or.
otherwise, so as to increase the velocity still further.
I do not limit myself to one set of the apparatus w and w¹, or to one arrangement
only of driving the belt or cord, as any of the well known means of driving may be
used. Neither do I limit the distance of these apparatuses from the axis of
rotation a x.
I am aware that, prior to my invention, vertical and horizontal centrifugal pumps
and ventilators were known, with wheels working in a similar manner; and I do not
claim such a combination broadly; but what I do claim as my invention, and
desire to secure by letters patent is :-
1. The combination, in centrifugal pumps and ventilators with axial discharge, of a
casing with an air tight cover c and helicoidal discharge tubes 1, or 1 and 2, or 1, 2
and 3, which receive the stream flowing from the wheel, without change of velocity,
leading it into the direction of the axis of rotation a substantially as herein before
described and shewn on the drawings.
2. The combination, in centrifugal pumps and ventilators with axial discharge, of a
casing with an air tight cover e and helicoidal discharge tubes 1 or 1 and 2, or 1, 2
and 3 the axes of which are either at equal distances to that of the fans from the
-axis-of-rotation-x-x,-or-increasing to a greater diameter, substantially as herein before
described and shewn on the drawings.
3. The combination, in centrifugal pumps and ventilators with axial discharge, of a
casing with an air tight cover c and helicoidal discharge tubes, 1, 2, the axis of which
are at constant distances from the axis of rotation ar, of a shaft supported between

page_text: t
the tubes by bearings upon the tablet y z, in such a manner that these supports may
be applied and perfectly adjusted at any height of the shaft directly, and without
disturbing any other parts of the construction, substantially as herein before described
and shewn on the drawings.
4. The combination, in centrifugal pumps to ventilators of one or more sets of
apparatus to for the application of manual power, each composed of driving
pullies ff and conducting pullies e el actuating the driven pullies à d¹, substantially
as herein before described and shewn on the drawings.
5. The general construction, combinations, and arrangements of the several and
respective parts, constituting my improvements in centrifugal pumps and ventilators,
substantially as herein before described and shewn on the drawings.
GEO. DOWNING,
Agent for Applicant.