NEW OR IMPROVED STEERING GEAR FOR SHIPS
Year: 1877

page_text: LETTERS PATENT to William Bruce Thompson, of Dundee, in the County of
Forfar, North Britain, for the Invention of "NEW OR IMPROVED STEERING
GEAR FOR SHIPS."
Sealed the 21st August 1877, and dated the 24th March 1877.
PROVISIONAL SPECIFICATION left by the said William Bruce Thompson at
the Office of the Commissioners of Patents on the 24th March 1877.
WILLIAM BRUCE THOMPSON, of Dundee, in the County of Forfar, North Britain.
"NEW OR IMPROVED STEERING GEAR FOR SHIPS."
This Invention, which relates to new or improved steering gear for ships, consists
of a shaft divided into two portions, one of which is cut with a right-hand and the
other with a left-hand screw. This shaft is provided at one end with a wheel or
equivalent mechanism for turning it. Nuts are placed both on the right-hand and
left-hand portions of the screw, these nuts being respectively connected to sliding
blocks. situate in slots made in the ends of a cross lever, which is fixed at its centre
on the upper extremity of the rudder post. Sleeves or guides are formed with or
attached to the nut, and into or through these rods or bars enter or pass so as to
prevent the nuts from turning with the screw when it is operated, and the said nuts
being thereby caused to move longitudinally and in parallel lines relatively with
each other, they, through the intervention of a cross lever, move the rudder to port
or starboard, according to the direction in which the screw is turned by the hand
wheel or other gearing upon its end.
In lieu of operating the screw by a hand wheel placed on one end of it, as set
forth, it may be operated by the engine which propels the ship, or from an inde-
pendent engine or other motor, by means of a chain or band, spur, bevel, or equiva-
lent gearing.

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Bruce Thompson in the Great Seal Patent Office on the 22nd
September 1877.
WILLIAM BRUCE THOMPSON, of Dundee, in the County of Forfar, North Britain.
NEW OR IMPROVED STEERING GEAR FOR SHIPS."
My Invention relates to new or improved steering gear for ships and like vessels,
and has for its object to render the said gear strong and simple in construction, and
speedy and sure in its action.
Steering gear constructed according to my said Invention consists of a central
shaft having formed upon it two screws, one having a right-handed thread, and the
other a left-handed thread. This shaft is rotated by a steering wheel, or by other
suitable means.
Upon both the right and left handed screw threads run corre-
spondingly threaded nuts, which are connected respectively with both ends of a yoko
or cross head mounted at its contre on the rudder post. On the rotation of the
central shaft, the said nuts being prevented by suitable means, as herein-after
described, from turning with the said shaft, travel upon their respective threads in
reverse directions, the one urging one end of the yoke or cross head on the rudder
post in one direction, and the other nut pulling the other end of the said yoke or
cross head in the other direction, or the reverse, according to the direction in which
the central shaft is rotated, thus putting the helm either to port or starboard.
And in order that my said Invention may be properly understood I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, reference being had to the
annexed Sheet of Drawings, and to the letters and figures marked thereon, that is
to say :-
Figure 1 represents a plan of steering gear constructed according to my said
Invention; and Figure 2 is an end elevation of the same.
The central shaft marked A turns in bearings in the end plates B, B', and has
formed upon it two screw threads, one a right-handed screw thread marked A¹, and
the other a left-handed thread marked A. One end of the said shaft A projects
beyond the end plate B', and is squared to carry the steering wheel or equivalent
device for rotating the said shaft. Upon each thread travel nuts C, C¹, having cast
therewith sleoves or guides D, D¹, running upon guido rods E, E¹, fixed in the end
plates on either side of the shaft A. One end of each of the sleeves or guides D, D¹,
is connected to each end respectively of the yoke or cross head F, fixed at its centre
on the end of the rudder post G, the connection being formed by pins d, d', passing
through blocks f,f', running in slots f³, fs, formed in the cross-head F. The end
plates B, B', are secured by bolts b, b¹, to standards H, bolted to the deck of the
ship or vessel.
The steering gear may be protected by a hood or other cover I, shewn in section
in Figure 1.
The action of the gear is as follows :— -On rotating the shaft A by the steering
wheel fixed on its end, or by the engine which propels the ship, or by other motor
through a chain or band, or through spur, bevel, or equivalent or suitable gearing,
as is well understood in connection with ordinary steering apparatus, the nuts C, C¹,
being prevented from turning with the said shaft by sheir sleeves or guides D, D¹,
travel upon their respective screw threads in reverse directions, and in lines parallel
to each other and to the shaft A, and by their connection with the yoke or cross
head F one of the ends of the said yoke or cross head is urged in one direction, and
the other end is simultaneously pulled in the reverse direction, the blocks f, f¹, by
running in the grooves f³, f³, allowing the said cross head to accomodate itself to
the motion of the said nuts. By this means the rudder is brought either port or
starboard, according to the direction in which the shaft A is rotated.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the system, mode, or manner in or under which the same is or may be

page_text: used or practically carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is, the improved steering gear
constructed essentially in the manner illustrated in and described with reference to
the accompanying Drawings.
In witness whereof, I, the said William Bruce Thompson, have hereunto set my
hand and seal, this Twentieth day of September, in the year of our Lord One
thousand eight hundred and seventy-seven.
W. B. THOMPSON. (L.S.)