AN IMPROVED PRO- PELLER, AS TO AFFIXING THE BLADES IN THE BOSS AND AFFIXING THE BOSSES TO THE SPINDLE OR CENTRE SHAFT, AND IN THE MODE OF PLACING IT, AND IN CONTROLING, LOWERING, AND DETACHING THE SAME
Year: 1853

page_text: i
LETTERS PATENT to John Buchanan, of Leamington, in the
County of Warwick, for the Invention of "AN IMPROVED PRO-
PELLER, AS TO AFFIXING THE BLADES IN THE BOSS AND AFFIXING THE
BOSSES TO THE SPINDLE OR CENTRE SHAFT, AND IN THE MODE OF PLACING
IT, AND IN CONTROLING, LOWERING, AND DETACHING THE SAME."
Scaled the 5th August 1853, and dated the 8th February 1853.
PROVISIONAL SPECIFICATION left by the said John Buchanan
at the Office of the Commissioners of Patents, with his Petition,
on the 8th February 1853.
I, JOHN BUCHANAN, of Leamington, in the County of Warwick, do
hereby declare the nature of the said Invention for "AN IMPROVED
PROPELLER, AS TO AFFIXING THE BLADES IN THE BOSS AND AFFIXING THE
BOSSES TO THE SPINDLE OR CENTRE SHAFT, AND IN THE MODE OF PLACING IT,
AND IN CONTROLING, LOWERING, AND DETACHING THE SAME," to be as
follows:-
My Invention consists of an improved propeller, which is placed
in a frame hinged to the stern post of the vessel, the same as a

page_text: rudder with an universal jointed shaft, and is so formed that each
blade can be feathered separately without cog wheels or clutches,
and, if of more blades than two; is so arranged on tue spinule that
the blades can be all placed vertically in line with the stern post or
frame in which the propeller acts, the said frame being controlled
by a double sliding tiller and screw wheel mounted on the auxiliary
tiller spindle acted on by a screw on the spindle of the steering
wheel, so that when the vessel is under canvass it forms a rudder
in connection with the frame and the above-mentioned controlling
apparatus, enabling the vessel to become a perfect sailing ship, and
can be lowered in connection with the auxiliary main shaft, to be
more out of the reach of shot, and also be detached with the false
tern post so as to be easily got at to clear or repair.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said John Buchanan in, the Great Seal
Patent Office on the 8th August 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOHN BUCHANAN, of Leamington, in the County of Warwick, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of February, in the
year of our Lord One thousand eight hundred and fifty-three,
in the sixteenth year of Her reign, did, for Herself, Her heirs
and successors, give and grant unto me, the said John Buchanan,
Her special licence that I, the said John Buchanan, my executors,
administrators, and assigns, or such others as I, the said John
Buchanan, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "AN IMPROVED PROPELLER, AS TO AFFIXING

page_text: THE BLADES IN THE BOSS AND APPIXING THE BOSSES TO THE SPINDLE OR
CENTRE SHAFT, AND IN THE MODE OF PLACING IT, AND IN CONTROLLING,
LOWERING, AND DETACHING THE SAME," upon the condition (amongst
others) that I, the said John Buchanan, by an instrument in
writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Buchanan, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the
Drawings annexed, that is to say:
My Invention consists of an improved screw propeller placed abaft
the stern post of the vessel in the position usually occupied by the
rudder, the use of which I propose to dispense with, as the said
propeller is intended both to steer and to propel the vessel, or to
steer her only when the propulsion is effected by means of the sails.
A frame is formed with two arms at right angles to each other,
one of which is vertical, and carries at its lower end a suitable
bearing for the after end of the axis of the propeller, and the other
of which is horizontal, and extends forward above the propeller,
carrying on the lower side of its fore end a pintle, which works into
a brace or gudgeon attached to a false stern post. The axis of the
propeller is connected at its fore end to the driving shaft by an
universal joint, in order that the rotary motion of the propeller may
not be interfered with when the frame and propeller are together
moved through any necessary angle for the purposes of steering.
Each blade of the propeller is fitted so as to be capable of rotating
in its boss, and when more than two are employed each of them
is made capable of rotating independently about the axis of the
propeller, so that the whole of them may be brought to very nearly
coincide with a fore and aft plane, when the propeller is to be em-
ployed for steering only, whereby all the qualities of perfect

page_text: sailing ship are retained, and the injurious effects arising from the
resistance of the ordinary screw when the vessel is under canvass
are entirely avoided, without the labor of raising the propeller, and
without the inconvenience of the aperture necessary for that
purpose. The transverse motion of the frame and propeller neces-
sary for steering is effected by means of a double sliding tiller and
a screw wheel mounted on an auxiliary tiller spindle, which is acted
upon by a screw on the spindle of the steering wheel. The blades
may be caused to rotate on their axes when necessary by means of
an instrument, which can be passed down through a vertical
aperture in the horizontal arm of the supporting frame, all cog
wheels and clutches being dispensed with. The apparatus, together
with the auxiliary main shaft, is fitted so that it may be lowered
when needful out of the reach of shot, and is capable also of being
readily detached with the false stern post for the purpose of cleaning
and repairing.
DESCRIPTION OF THE DRAWINGS.
Figure 1, A, A, represent a longitudinal section of a ship or vessel
fitted with my propeller; B, B, is the false or shifting post; C, the
driving shaft; C¹, the axis of the propeller; D, a vertical shaft for
carrying the tiller; E, E, the frame which supports the propeller;
F, F, braces or gudgeons, in which the pintle of the frame E, E,
rotates, and which have the centres of their holes in a line with the
centre of the universal joint M, M; G, G, are the propeller blades,
which work on their extremities H, H, as pivots in the bosses
K, K; Q, is the aperture in the frame E, E, through which the
instrument by which the blades are turned may be passed.
Figure 2, N, N, represent a four bladed propeller. The various
parts of it are marked with the same characters as those which were
affixed to corresponding parts in Figure 1. In this propeller the
foremost bosses are permanently fixed to the axis C¹, C¹, but the
after ones are capable of partially rotating round it, the limit of their
revolution when propelling being fixed by the snuggs x, x, which
work in grooves formed in the after end of the foremost boss, as

page_text: shewn in the Figure, and which grooves are of such a length as to
allow the snuggs to move in them until the four blades of the pro-
peller come nearly into the same plane, but no further, when the
vessel may have overrun the propeller, or when the instrument is
needed for steering only.
And having now described the nature of my said Invention, and
in what manner the same is to be performed, I declare that what I
claim is, the general arrangement of apparatus for propelling and
steering ships or vessels as herein-before described, and represented
in the Drawings annexed.
In witness whereof, I, the said John Buchanan, have here-
unto set my hand and seal, this Fifth day of August, One
thousand eight hundred and fifty-three.
JOHN BUCHANAN. (L.S.)