Improvements in Screw-propellers.
Year: 1894

page_text: Date of Application, 6th Mar., 1894
Complete Specification Left, 28th Nov., 1894-Accepted, 29th Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in Screw-propellers.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by Carl Meissner, of Hopfensack 11, Hamburg, in the Empire of Germany,
Engineer) to be as follows:-
This invention relates to screw-propellers having reversible or feathering
blades.
According to this invention the alteration of the pitch of the blades is effected
through the medium of a plate adapted to be moved in the direction of the axis of
the propeller shaft and having slots with which crank pins upon discs fixed to the
stems or journals of the blades engage. The adjacent ends of the blades support
one another by working upon or being connected with a coupling. The blades are
each screwed from outside the boss into an annular nut held in position and
prevented from turning by a bush screwed into the propeller boss and secured by a
nut lock gripping over the bush.
Dated this 6th day of March 1894.
I, GEORGE FREDERICK REDFERN, of the Firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of London,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by Carl Meissner, of Hopfensack 11, Hamburg, in the Empire of Germany,
Engineer) 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 screw-propellers having reversible or feathering
blades.
According to this invention the alteration of the pitch of the blades is effected
through the medium of a plate adapted to be moved in the direction of the axis
of the propeller shaft and having slots with which crank-pins upon discs fixed
to the stems or journals of the blades engage. The adjacent ends of the blades
support one another by working upon or being connected with a coupling. The
blades are each carried by a bush screwed into the propeller boss and secured by a
nut-lock gripping over the bush.
To enable the invention to be fully understood I will describe the same by
reference to the accompanying drawing, in which :-
Figure 1 is an elevation partly in section of a propeller constructed according to
my invention :

page_text: Figure 2 is a longitudinal section of the same; and,
Figure 3 is a transverse section on the line 3-3, Figure 2.
a is the hollow boss of the propeller which at one end is adapted to be screwed or
otherwise fixed to the shaft band at the other end provided with a removable cap c
for affording access to the interior of the said boss. d, d' are the propeller blades
the shank of each of which is adapted to partially rotate in a bushf externally
screw-threaded and screwed into a boss g on the inside of the boss a.
The
shanks e, e of the said blades at their adjacent ends are connected together so as to
afford rigidity. As shewn in the drawings, the shank e of the blade d is provided
with a hole into which a pin on the shank of the blade d' is designed to
enter.
To prevent the blades from moving longitudinally or from falling out of the
bushes, fa collar or nut i is screwed onto each shank behind the bush f, as clearly
shewn in Figure 3.
1, are the cranks, and k is the plate having slots 1, I therein with which the
pins of the cranks j engage and by means of which the blades are moved.
The platek slides on guides m, m inside the boss and has connected to it a rod n
extending through the propeller-shaft b and by means of which the said plate is
operated. The cranks, are fitted onto square-shaped portions of the shanks e, e,
the pin of one crank being arranged to project to one side of the boss a and the
pin of the other crank to the opposite side in such a manner that, when the said
plate is moved, the blades will be correspondingly moved one in one direction and
the other in the opposite direction.
In fitting the parts of the propeller together the bushes f, fare first of all placed
in position upon the shanks e, e and then the collars i, i are screwed onto the
shanks to hold the said bushes in place. The plate kis then placed in position in
the boss a and the cranks, are also placed so that their pins, engage with the
slots 1, in the plate k. The blades are now placed in the boss a in such a position
that as the bushes f,fare screwed into the lugs g, g the square portions of the
shanks will be caused to enter the corresponding openings in the cranks and in the
proper relative position with the latter, the pin on the shank of one blade entering
at the same time the hole in the shank of the other. The cap c of the boss is finally
fixed in position.
In order to prevent the bushes f, f from becoming unscrewed inadvertently,
locking-pieces o, o are made use of, the said locking-pieces being inserted and
secured in recesses formed on the outer surface of the boss a and having their ends
bearing upon flanges of the bushes f, f; a collar p at the root of each blade
being cut away, as shewn in Figure 1, to allow of the said locking-pieces projecting
over the said Hanges. The projections q, 9 formed by thus cutting away the collar p
serve as stops or abutments for limiting the movement of the blades in either
direction, the said abutments impinging against the locking-pieces o, o. As shewn
in the drawing, the parts are represented in the position in which the surfaces of
the blade are in a plane at right angles to the axis of the propeller; it is to be
understood, however, that when the propeller is in use the blades assume a position
in which one or the other of the abutments q is in contact with the stops o.
Having now particularly described and ascertained the nature of the 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 having feathering blades, operating the said blades by
means of a sliding-plate such as k engaging with the pins of cranks upon the
shanks of the blades, substantially as described by reference to the accompanying
drawing.
2. In a screw-propeller having feathering blades, mounting the blades in bushes
adapted to be screwed into the boss of the propeller, and holding them in the said
bushes by nuts or collars, the said blades at their inner ends being connected or
coupled, substantially as described.

page_text: 3. The combination of parts forming the improved screw-propeller with feathering
blades substantially as hereinbefore described and illustrated in the accompanying
drawing.
Dated this oth dow of Nombor 1901
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.