Improvements in Machinery for Propelling Ships.
Year: 1888

page_text: Date of Application, 17th Nov., 1888
Complete Specification Left. 17th Aug.. 1889-Accepted. 21st Sept.. 1889
PROVISIONAL SPECIFICATION.
Improvements in Machinery for Propelling Ships.
I, GEORGE ALFRED POOLE, of Askearn near Doncaster in the county of York,
Clergyman do hereby declare the nature of this invention to be as follows :-
This invention is an improvement upon the patent, No. 9139, 1886. The stern
cylinder therein described is retained, unaltered, with the exception of the air shaft,
which is now dispensed with, the inner end of the cylinder being entirely closed,
excepting the stuffing-box, through which the propeller shaft passes.
The propeller instead of closely fitting the cylinder in which it works, is now made
considerably smaller, only about five-sixths of the inside diameter of the cylinder,
leaving an annular space through which water is freely admitted into, and expelled
from the cylinder alternately. The form of the propeller somewhat resembles a
saucer, being concave upon the side seen from the open end of the cylinder, and
convex upon the other side, tapering to a hub in the centre, so as to give sufficient sub-
slanco at that part, to allow it to be firmly and securely fixed upon the shaft. The stern
cylinder was shewn in the patent above mentioned, to be entirely within the vessel.
This is doubtless the best position for it in a war-vessel, but in others a lower position
may be obtained by placing it outside, resting immediately upon the keel of the vessel
prolonged for the purpose; or in the case of vessels built of iron or steel, the stern
of the vessel itself may take the form of a cylinder below the water line, having a
circular hulk-head, with central stuffing box for the propeller shaft to pass through,
to form the closed end of the cylinder.
Datod this Sixteenth day of November 1888. ·
COMPLETE SPECIFICATION.
Improvements in Machinery for Propelling Ships.
I, George Alfred POOLE, of Askearn near Doncaster in the county of York,
Clergyman, 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 is an improvement upon the patent No. 9139, 1886. The stern
cylinder therein described, is retained, unaltered, with the exception of the air shaft,
which is now dispensed with, the inner end of the cylinder being entirely closed,
excepting the stuffing-box, through which the propeller shaft passes. The propeller
instead of closely fitting the cylinder in which it works, is now made considerably
smaller, only about five-sixths of the inside diameter of the cylinder, leaving an
annular space through which water is freely admitted into and expelled from the
cylinder alternately. The form of the propeller somewhat resembles a saucer, being
concave upon the side seen from the open end of the cylinder, and convex upon the
other side, tapering to a hub in the centre, so as to give sufficient substance at that
part, to allow it to be firmly and securely fixed upon the shaft. The stern cylinder
may be entirely within the vessel, or it may be outside, and joined on to the vessel in
such a way as to appear to be a portion of the hull; the stern of the vessel being
shaped or tapered to coincide with the inner end of the cylinder, the cylinder being
securely attached to the vessel by means of bolts or rivetted plates. The weight of
the cylinder will be partially sustained by the keel of the vessel upon which it will
rest and to which it will be secured.
In order that my invention may be fully understood I will proceed to describe how
the same can be carried into practice by reference to the accompanying drawing.

page_text: The drawing shews in section the cylinder A, with the propeller B, within the
cylinder, and mounted upon shaft C, which passes through the stuffing-box D, and is
coupled to engine not shewn in the drawing.
The cylinder A. is always more or less full of water, as at the outward thrust of
the propeller a large portion of the water present is expelled, at the same time other
water enters by the annular space between the propeller and the cylinder, and is in its
turn expelled by the return stroke of the propeller.
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. The manufacture and use of a propeller substantially as hereinbefore described
and illustrated in the accompanying drawing.
Dated this 16th day of August 1889.