A NEW OR IMPROVED SHIP'S PROPELLER
Year: 1885

page_text: I, ALBIN FRANZ BARTH of Grossenhain, Saxony, Engineer, do hereby declare the
nature of my invention for A NEW OR IMPROVED SHIP'S PROPELLER, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
▸
The centrifugal propeller represented in the accompanying drawings, and
hereafter described, is chiefly characterised by the circumstance, that the turbine
acts, partly, like an ordinary paddle-wheel and, partly, like a centrifugal suction-
wheel.
}
Not only is the water, which is taken up direct by the bottom of the wheel, set
in motion, but, owing to the centrifugal force, water is also drawn in at the side (in
the centre) and thrown under the wheel to the back, as in the case of an ordinary
paddle-wheel.
By this combined action, large masses of water are set in motion by a propeller
of small dimensions, and great speed may be used without much loss of force.
Figs I, II and III represent the details of a centrifugal propeller in horizontal
section, longitudinal vertical section and cross section. The casing g is open below;
a is the shaft of the moveable paddle-wheel; b represents the blades of the paddle,
the lower part of which projects beyond the ship's bottom; c. c represent the side
of the paddle-wheel box, the wheel being exposed below, and d, d are openings in
this casing, through which the water from the suction-chamber e can have access to
the centre of the paddle-wheel, which, as before said, throws it against the casing,
drives it round and throws it backward.
'
The section of each suction-chamber may be that of a truncated cone whose
upper edge coincides with the circular aperture d. Below, the suction-chamber
widens out to the full width of the open casing, and is also open at the bottom, like
the latter.
The open part of the casing and of the suction chamber corresponds, therefore, to
an opening in the bottom of the vessel, which leaves the inside of the casing and
the suction-chamber open or accessible from below. The way, in which the casing
and the suction-chamber are composed of several parts, is determined by the nature
of. the circumstances, and can be effected in various manners.
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For instance, the casing and the suction-chambers can be made of an upper and
a lower half connected together by flanges.
For bedding and packing the shaft in small ships, the appliances shown in the
drawing are used. These appliances consist of axle-bearings cast on to the main
wall, which, at the same time, form the stuffing-box behind; moreover, of the glands
which are here used as prolongations of the bearings.
The bushes must be provided with appliances for withdrawing them, for instance,
shallow tapped holes, into which pins are screwed, before the bearings are
withdrawn.
In large ships, the shaft can be specially bedded outside the casing and the
suction-chamber.
In this case, the shaft, passes through the stuffing-boxes in the main walls of the
suction-chamber, and, in order to prevent trouble in taking the glands out of the
stuffing-boxes when the bearings are but a short distance apart, the glands can be
made in several pieces.
Of these, the head-pieces only (like ordinary glands consisting of one, two or
more pieces) are screwed together over the shaft; the other pieces, also provided
with appliances for withdrawing them, are placed loose in the stuffing-box.
The lower part of the casing and the suction-chamber is an accessory of the hull
and is made in one piece with it.
The same applies to the lower part of the side-walls c for the paddle-wheel
which is otherwise exposed at this point, but the form of the side-walls may be
varied.
The blades of the paddle may be quite flat (Fig. III), or curved or formed in any
suitable way.
As a protection against large floating bodies, the suction-chamber may be provided
with small bars or a grating.
In vessels which are to be fitted with the centrifugal propeller, the upper part of
the hull (in the stern of which the propeller is placed) must project sufficiently
over the rear of the lower part as is requisite for mounting the propeller.
The lower part of the hull may be flat-bottomed or provided with a keel.
In the first case, the lower part need not be deeper than is required by the
-exposed portion of the paddle-wheel, and, in no case, must it be so deep that the
upper part does not enter the water,
The after-part of the upper-hull is always provided with a flat flooring, so that
the propeller can be conveniently mounted.
..
Instead of a single propeller, two adjacent propellers can be mounted in the after
part on the same shaft or independently of each other.
In this case, each propeller requires one suction-chamber only, namely, on that
side of the vessel where the paddle-casing is situated.
'
Figs IV, V and VI represent a flat-bottomed vessel with only one propeller, in
plan, longitudinal and cross section.
If only one propeller is employed, the steering-gear is placed behind the same, as
in screw-steamers (see Fig. V) or otherwise; in the case of two propellers, the lower
after-part of the hull forms a prolongation in the middle between the two exposed
parts of the paddles, and to this the steering apparatus is attached.
This arrangement of the lower hull can also be applied in vessels with one
propeller, if the wheel, (but not the shaft) is divided into two vertical sections, so
that both halves of the wheel are contained in the same casing.
:
..In this case, the interior of the casing may also consist of two compartments but
there must be a space left in the partition for the passage of the shaft.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
The combination of a pressure-propeller with a reaction propeller, consisting of
a partly-encased paddle-wheel, the lower part of. which is exposed at the front and

page_text: at the back, and to which water is conveyed by suction through lateral apertures
or suction chambers, in order to combine the direct pressure of the paddle-blades
with the reaction of a stream of water which is sucked up and then thrown out
behind, for the purpose of increasing the total effect.