Improvements in Screw-propellers.
Year: 1896

page_text: Date of Application, 2nd Mar., 1896
Complete Specification Left, 2nd Dec., 1896-Accepted, 9th Jan., 1897
Improvements in Screw-propellers.
I, CARL AUGUST FERDINAND MEISSNER, of Hopfensack 11, Hamburg, in
the German Empire, Engineer, do hereby declare the nature of this invention to
be as follows:
This invention relates to improvements in screw-propellers with reversible
blades of that class in which the alteration of the pitch of the blades, or their
reversal, is effected through the medium of a sliding plate or block adapted to be
moved within the propeller boss in the direction of the axis of the propeller shaft,
and to, accordingly, act upon the crank arms or discs fixed to the stems or journals
of the blades. The present invention comprises certain peculiar constructional
features of the sliding plate or block and of the crank arms or discs of the blades,
whereby the operative length of the lever arms between the sliding element and
the journals of the blades will be in conformity with the increase or decrease of
the water pressure upon the blades in their different positions, so that adequate or
nearly adequate power is ensured to operate the ineans for transmitting the
necessary motion from the interior of the vessel to the said sliding piece .connected.
with the blades or their crank arms, respectively. The invention also comprises
certain new arrangements or means whereby the blades or their journals, respectively,
are properly secured and reliably guided in the propeller boss, in order to prevent
jamming and friction, thereby enabling the blades to be rotated with greater
facility.
According to the present invention, the alteration of the pitch of the blades, or
their reversal, is effected by means of a sliding plate, block, prism or the like,
suitably arranged within the hollow boss and adapted to be moved by suitable
means in the direction of the propeller shaft. For this reason, the said sliding
piece is provided with pins which engage with slots or notches of the crank arms
fixed to the journals of the blades.
In order to avoid jamming of the journals and to secure a reliable bearing of
the blades in the boss, the cranks may receive the shape of notched discs and may
be made, preferably, in one piece with the corresponding journals, so as to form
large flanges at the inner extremities of the said journals projecting through
suitable sockets into the boss. The flange like crank discs take a circumferential
bearing in and upon a corresponding seat in the inner wall of the boss, and are
supported and secured in their proper position by the said sliding piece itself
arranged for this purpose to slide between the said crank flanges in such a manner
that when the said sliding piece is moved in one or the other direction, the blades
will be moved correspondingly and at the same time held at the proper distance
apart.
The boss itself may be arranged and constructed as may be requisite according
to the particular circumstances of the case.
Dated this 2nd day of March 1806
PHILLIPS & LEIGH,
Agents for the Applicant.

page_text: 1, CARL AUGUST FERDINAND MEISSNER, of Hopfeusack No. 11 Hamburg, im
the German Empire, Engineer, do hereby declare the nature of this 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 improvements in screw propellers with reversible blades
of that class in which the alteration of the pitch of the blades, or their reversal, is
effected through the medium of a sliding plate or block adapted to be moved
within the propeller boss in the direction of the axis of the propeller shaft, and to,
accordingly, act upon the crank arms or dises fixed to the stems or journals of the
blades. The present invention comprises certain peculiar constructional features
of the sliding plate or block and of the crank arms or discs of the blades, whereby
the operative length of the lever arms between the sliding element and the journals
of the blades will be in conformity with the increase or decrease of the water
pressure upon the blades in their different positions, so that adequate or nearly
adequate power is ensured to operate the means for transmitting the necessary
motion from the interior of the vessel to the said sliding piece connected with the
blades or their crank arms, respectively. The invention also comprises certain
new arrangements or means whereby the blades or their journals, respectively, are
properly secured and reliably guided in the propeller boss, in order to prevent
jamming and friction, thereby enabling the blades to be rotated with greater
facility.
To enable the invention to be fully understood, 1 will describe the same by
reference to the accompanying drawing, in which :-
Figure 1 is a longitudinal, and
Figure 2 a transverse, section of a propeller constructed according to my
invention:
Figure 3, an end view without the rear cap, and
Figure 4, a longitudinal section of a modification of my improved propeller.
Figures 5 and 6 are detailed sectional views showing the sliding piece in different
working positions.
Similar letters refer to similar parts throughout the several figures.
The hollow boss a of the propeller (Figures 1 and 2) is at one end adapted to be
screwed or otherwise fixed to the hollow shaft & and at the other end provided with
a removable cap c.
The journals or stems d of the blades d' are mounted in suitable
bearings of the boss a and adapted to partially rotate therein. Upon each shank d
is screwed a suitable crank-arme having a suitable slot or notch e. These crank-
arms e, which are secured in the proper position upon their respective shanks by
means of suitable cross pins, prevent at the same time the blades from moving
longitudinally or from falling out of the boss or bearings respectively. To afford
rigidity the shanks of the blades are suitably connected together at their adjacent
ends. As shown in the drawing the shank of one blade is provided with a hole or
recess into which a pin or stud d on the shauk of the other blade is designed to.
enter.
The alteration of the pitch of the blades, or their reversal, is effected by means
of a sliding block or plate g. This plate y slides on guides h inside the boss and
has connected to it a rud i extending through the propeller shaft and by means
of which the said sliding piece is operated. The latter is provided with pins k
which engage with the slots e of the crank arms e. The arrangement of the parts
being thus that when the plate g is moved, the blades will be turned or moved

page_text: correspondingly one in one direction and the other in the opposite direction. As.
shown in Figures 1 and 2, the parts are represented in the position in which the
surfaces of the blades are in a plane at right angles to the axis of the propeller.
To avoid jamming of the journals and to secure a reliable bearing of the blades.
in the boss, the cranks may receive the shape of notched discs e, es, (see Figures 3.
to 6 in which I have shown a screw propeller provided with four blades), and may
be made, preferably, in one piece with the corresponding journals d, so as to form
large flanges at the inner extremities of the said journals projecting through suitable
sockets into the boss a' which has a somewhat modified form. The flange like
crank discs take a circumferential bearing in and upon a corresponding sent a
in the inner wall of the boss a', and are supported and secured in their proper
position by the sliding piece g' itself which for this purpose is made prismatic and
arranged to slide between the said crank flanges in such a manner that when the
sliding prism g is moved in one or the other direction, the blades will be held at
the proper distance apart and at the same time rotated correspondingly by means
of the pius attached to the sliding prism g' and engaging with the notches e³ of
the crank disc e².
The boss itself may be bipartite or arranged and constructed as may be requisite
according to the particular circumstances of the case.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a screw-propeller with reversible blades, a sliding plate, block; prism or
the like suitably arranged within the hollow boss of the propeller and adapted to
engage with slots or notches of crank arms, discs or the like fixed to the stems or
journals of the blades, substantially as and for the purpose set forth.
2. In a screw-propeller having reversible blades the combination of a sliding
plate g provided with pins k, with crank arms e fixed to the journals of the blades
and having slots e', the said pins k engaging with the said slots e', substantially as
specified.
3. In a screw-propeller having reversible blades the combination of notched
crank discs ce fixed to the journals of the blades or made in one piece with the
same, of a boss a' having suitable bearing seats a' for the said flange like crank
discs, and of a sliding prism gadapted to secure the said crank discs in their
respective bearing seats, to bold the blades at the proper distance apart and to
operate the latter by means of pins attached to the said sliding prism and
engaging with the notches e of the crank discs e, substantially as described.
4. The combination of parts forming the improved screw-propeller with
reversible blades, substantially as hereinbefore described and illustrated in the.
accompanying drawing.
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,.
Agents for the Applicant.