IMPROVEMENTS IN STEAM ENGINES AND PROPELLERS FOR PROPELLING VESSELS
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Cortland Herbert Simpson at the
Office of the Commissioners of Patents, with his Petition, on the 19th
November 1866.
I, CORTLAND HERBERT SIMPSON, of Bexhill, in the County of Sussex,
Captain Royal Navy, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN STEAM ENGINES AND PROPELLERS FOR PROPELLING VESSELS,"
to be as follows:-
My Invention relates to improvements in propelling apparatus, and to that
class of propellers for propelling vessels consisting of a rotating cylinder or
drum disposed below the water line, from which cylinder blades or paddles
are projected during a certain portion of the revolution to act upon the
external water, or it may be on water passing through a channel and discharged
to produce the effect of propulsion on the vessel. Instead of transmitting power
to the axis of such propeller from a steam engine, as heretofore proposed, I
construct the steam engine and the rotating cylinder carrying the paddles in
one, that is to say, instead of simply forming radial recesses in the said rotary
cylinder to receive the blades or pallets, I dispose a steam cylinder or cylinders
in line with each pallet or blade, the said pallets, paddles, or blades being each
directly connected with such steam cylinder or cylinders by a suitable piston

page_text: rod or rods; or the blades or pallets themselves may lead directly from the
steam pistons. Supposing there are sixteen pallets disposed in the circumference
there will be a steam chamber or cylinder or cylinders corresponding with each,
disposed radially, having the inner ends abutting on the central capacity forming
the centre of the wheel, and which serves as its axis, being mounted in suitable
gudgeons or bearings, one on either side. In this centre cavity is placed a
stationary cylinder or tube fitted somewhat accurately to the other; this
stationary capacity is furnished with diaphragms, which divide it into induction
and eduction passages for the steam. The pallets or blades are controlled in
their position by guide rollers or studs traversing stationary cam grooves disposed
at either side of the wheel or drum, and according to which cam grooves
the pallets or blades are projected from or withdrawn within the periphery.
The pallets are kept in the projected or partially projected position about
one-fourth of a revolution and in the collapsed position about three-fourths of
a revolution, consequently the cam grooves are formed of different diameters
corresponding with such positions, the extremes being united by inclined or
curved junction parts forming a continuation of the cam grooves. This propeller
is caused to rotate by the force of the steam admitted to the steam chambers or
cylinders before mentioned, which operate on the pallets, and cause them to
be thrust outwards at the proper time. This takes place in each cylinder
at the time the pallet guide enters upon the incline of the cam groove when
passing from the smaller to the larger radius, causing the wheel to be impelled
in a circular direction. The withdrawal of the pallets or blades at the other
inclined part (the course from the larger to the smaller radius) may also
impel the wheel round in like manner by the vacuum in the cylinders, or steam
operating in the reverse direction, thus the projection or withdrawal of the
pallets by the steam power rotates the wheel, the pallets at the same time
being projected into the external water propel the vessel. Steam is admitted
to the cylinders at the proper time and during a certain portion of the revo-
lution, that is to say, while a pallet is traversing the incline of the cam grooves
by an opening cut in the inner stationary tube or cylinder before mentioned,
which opening acts as a valve or slide and keeps all the other cylinders closed
from the induction steam. A similar opening coinciding with the position of
the inward incline communicates with the eduction pipe and affords escape
for the steam from the cylinders and communication with the condenser, which
I propose shall be formed in the lower or outer part of each hollow pallet or
float, which act either as surface condensers or by means of injection as most
convenient, or an external condenser fitted in the usual manner may be used.

page_text: By simply changing the induction steam passage to the eduction and vice versa,
the propelling wheel will be rotated in the opposite direction. Instead of the
pallets or blades being projected into the external water at the bottom or sides
of a ship they may operate in a channel opening in the one direction to the
external water, and in the other direction be carried above the water line, and
so as to discharge the water above that level whereby to produce a propelling
effect.