IMPROVEMENTS IN APPARATUS FOR PROPELLING AND STEERING. SHIPS OR VESSELS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
8th November 1875.-A communication from abroad by Romnalde
Schiaffino, of Paris, in the Republic of France.
°
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR PROPELLING AND STEERING.
SHIPS OR VESSELS," a communication to me from abroad by Romnalde
Schiaffino, of Paris, in the Republic of France, to be as follows:-
-
This Invention relates to apparatus for steering and propelling sailing
vessels, and it consists in the employment of a small moveable screw
arranged in a frame between the two uprights of the poop or stern posts
in the place where the propeller of screw ships is situate, which screw
not only partakes of a rotary motion imparted to it by a small steam
engine in order to propel the vessel when required, but is also capable of
being turned at an angle so as to form an auxiliary apparatus for steering
the vessel during tempests, or in the case of the rudder breaking, or at
other times if desired.

page_text: The second or steering motion of the screw is obtained by means of
mechanism arranged upon the deck under the control of the pilot.
In carrying out this Invention a horizontal sleeve or hollow shaft is
provided for the passage of the shaft for working the rudder proper, on
which hollow shaft there is mounted a bevel pinion, whence motion is
imparted to a frame carrying the screw through the intervention of the
gearing herein-after mentioned. The bevel pinion carried on the hori-
zontal shaft is in gear with a bevel wheel mounted on the upper end of
a vertical shaft, to the lower end of which there is secured another
bevel wheel, which drives a bevel pinion carried on another horizontal
shaft. On this shaft there is mounted a worm engaging with a worm
wheel fast on another vertical shaft, which extends downwards, and is
united to the frame in which the small propelling and steering screw
above mentioned is carried. A hand wheel to be manipulated by the
pilot is provided on the hollow shaft first mentioned, by the act of
turning which the frame, and with it the screw, is moved round so as
bring it at an angle to the vessel, whereby the latter is steered in the
desired course.
In order to cause the screw to rotate for the propulsion of the vessel
motion is imparted from the steam engine by means of gearing to a
. horizontal shaft carrying a bevel wheel, which drives another bevel wheel
mounted loosely on a vertical shaft forming a part of the frame of the
propeller, from which latter wheel motion is transmitted to another bevel
wheel fast on the hub of the screw.
:
The shaft for transmitting motion from the engine to the bevel gearing
driving the screw is made hollow for the introduction of two devices in
its interior, one of which is intended to fix the blades of the screw upon.
the hub in the most favorable position, to which position they may be
readily adjusted by the second device, as herein-after explained. The
blades of the screw are consequently made capable of turning for a
quarter of a circle upon the hub itself, for which purpose they aro
attached to the hub by means of a spindle arranged at right angles to
its axis, and carrying bevel wheels, to which motion is imparted by
another bevel wheel rotated by means of a longitudinal ròd passing
through the centre of the shaft.
After placing the blades in a suitable position on the hub, either for
acting as a screw proneller or no
rudder they are scoured in their

page_text: adjusted position by means of a hollow tightening rod enclosed within
the hollow shaft, and by the act of turning which a jam nut screwed on
to the hub is tightened so as to render the bevel gearing immovable.
.
In order to avoid the introduction of foreign substances in this last-
mentioned mechanism which might form an obstacle to the said move-
ments, an automatic diaphragm is employed for closing the corre-
sponding orifice under the action of a counterweight as soon as the
apparatus for turning and fixing the blades of the screw has been
withdrawn.