Improvements in Screw Propellers.
Year: 1888

page_text: Date of Application, 21st Dec., 1888
Complete Specification Left, 20th Sept., 1889-Accepted, 26th Oct., 1889
PROVISIONAL SPECIFICATION.
Improvements in Screw Propellers.
I, CARL CHRISTIAN DAEVEL, of Kirchhofsallée 58 Kiel, Germany, Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to screw propellers, and its object is to provide means for
altering the position of the blades upon the boss in order to stop or reverse the course
of a ship independently of the direction of the rotation of the main shaft.
To carry this invention into effect, the hollow boss, or hub, of the propeller is made
in two parts fitting the one into the other, and these are held together by means of a
nut at the rear end of the propeller shaft or by other equivalent means. The joint of
the hub coincides with the plane of rotation, in which lies the axis of the blades, and
is rebated or chamferred so as to form a water-tight joint. Each of the blades, which
is adapted to turn about its axis in a bearing in the wall of the hub, is also provided
at the end of its pivot, which extends into the cavity of the hub, with an arm or crank.
The latter is connected by a link to a sleeve on the screw-shaft. The latter is hollow
in order to receive a rod which is at one end connected with the said sleeve and at
the other end with a suitable reversing lever or device.
The action of my invention will be as follows:-
The rod above mentioned is pulled or pushed by the reversing lever, and the motion
thereof is communicated through the links and cranks above mentioned to the blades
simultaneously, which will be accordingly moved, each one in its bearing in the hub-
wall about its own axis, and its working position altered accordingly.
Dated this 21st day of December 1888.
COMPLETE SPECIFICATION.
Improvements in Screw-propellers.
I, CARL CHRISTIAN DAEVEL, of Kirchhofsallée, 58, Kiel, Germany, 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:
My invention relates to screw propellers, and its object is to provide means for
altering the position of the blades upon the boss in order to stop or reverse the
course of a ship independently of the direction of the rotation of the main shaft.
In order that my invention, and the means by which the same is to be carried
into practical effect, may be thoroughly understood, I will now describe them in
detail, referring in so doing to the accompanying figures, in which
Fig. 1 is a longitudinal section.
Fig. 2 is a transverse vertical section through the propeller boss.
The hollow boss, or hub, of the propeller is made in two parts h¹ fitting the one
into the other at j; and these are held together by means of a nut a at the rear end
of the propeller shaft g, or by other equivalent means. The joint of the hub
coincides with the plane of rotation, in which lies the axis of the blades, and is
rebated or chamferred so as to form a water-tight joint.
Each of the blades, which is adapted to turn around its axis in a bearing k in the
wall of the hollow hub h h¹, is also provided at the end of its pivot i with an arm or
crank b which is connected by a link c to a sleeve d on the screw shaft g. The latter
is made hollow in order to receive a rod e which is at its rear end connected with the
said sleeve d; and at its fore-end, by means of the axially movable bushing or sleeve l,
with a suitable reversing device or lever f.

page_text: The action of my invention will be as follows:-
The rod e is pulled or pushed by the reversing lever f, or by other equivalent means,
and the motion thereof is communicated through the sleeve d, the links c and the said
arms or cranks b, to the blades simultaneously, which will be moved, each one in its
bearing in the hub-wall about its own axis, and its working position altered
accordingly.
In order to prevent water entering through the hollow shaft and the connecting
parts of the reversing lever with the rod e into the engine room, the sleeve or bushing?
is fitted at both ends with stuffing-boxes m m³, and in order to better preserve the
inner working parts of the propeller-shaft and the hub both the latter may be filled
with a suitable lubricant.
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:
In combination with a screw-propeller having movable blades adapted for having
their working positions altered, the axially movable rod e within the hollow shaft y,
connected at one end by the aid of the sleeve d, links c and cranks b, to the blades of
the propeller, and at the other end to the reversing device, substantially as and for the
purpose specified.
Dated this 20th day of September 1809.
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, W.C., Agents for the Applicant.