IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS
Year: 1872

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS."-A communi.
cation from abroad by William Condell, of the City, County, and
State of New York. United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 10th February 1872.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS," to be
as follows: -
This Invention relates to a new and important improvement in
the mode of propelling vessels through the water, adapted alike
to propelling vessels on lakes, rivers, and canals, as well as on the

page_text: ocean, and consists in a series of double-action propelling blades,
more or less in number, attached to a sliding plate actuated by means
of a reciprocating rod attached thereto or connected therewith, the
construction and arrangement being as hercin-after more fully described.
The blades are pivoted to a sliding fulcrum plate, said pivots being 5
fulcrums for each blade, the blades being made to act as levers. The
motive power is applied to a reciprocating rod connected with the blade
by means of jaws, which form the short end or arm of the lever blade.
A pin passes through these jaws and through the rod, so that when the
rod is moved longitudinally back and forth the blades or floats will 1
work on their fulcrums, and open and close and move with the rod.
The sliding plate and the blades thereon may be operated otherwise
than by the reciprocating rod, as for instance by a vertical vibrating
lever connected with the motive power. The plate to which the blades
are pivoted slides in grooves formed by cleats on a circular stationary 1
plate.
Shoulders are formed on the short arms of the blades which strike
the sliding plate when said blades are at right angles thereto.
The blades are thrown to a right angle with the fulcrum plate at the
first movement of the reciprocating rod, and then the blades and the 2
plate partake of the reciprocating motion of the rod, which may be
more or less in extent. On the back stroke the blades are instantly
closed against the sliding plate.
For backing the boat the blades are simply opened and closed, the
sliding plate being held stationary by any mechanical device provided 2
for the purpose.
These propellers are attached to the sides of the vessel beneath the
water line, and arranged in any manner so that a reciprocating motion
may be imparted to the short end of the blades and to the sliding
plate.
3

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 9th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of February, in the year
of our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, 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 "IM-
PROVEMENTS IN APPARATUS FOR PROPELLING VESSELS," a communication to
me from abroad by William Condell, of the City, County, and
State of New York, United States of America, upon the con-
dition (amongst others) that I, the said Alexander Melville Clark,
my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, 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 Alexander Melville Clark, do hereby
declare the nature of the 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 accompanying
Sheet of Drawings, and the letters and figures marked thereon (that is
to say):
:-

page_text: pelling vessels on lakes, rivers, and canals, as well as on the ocean, and
consists in a series of double-action propelling blades, more or less in
number, attached to a sliding plate actuated by means of a reciprocating
rod attached thereto or connected therewith, the construction and
arrangement being as herein-after more fully described.
DESCRIPTION OF DRAWINGS.
Figure 1 represents a vertical longitudinal section of a propeller of
three blades, which blades are extended as when propelling or at work.
Figure 2 is a vertical longitudinal section, showing the blades closed, as
when on the back stroke; both of said sections being taken on the
line x, x, of Figure 3. Figure 3 is a vertical cross section of Figure 1
taken on the line y, y.
Similar letters of reference indicate corre-
sponding parts.
A represents the blades. B is a sliding fulcrum plate, to which the
blades are pivoted, said pivots being fulcrums for each blade, the blades
being made to act as levers. C is a reciprocating rod, to which the
motive power is attached. This rod is connected with the blade, as
seen in Figure 3, by means of the jaws D, D, which form the short end
or arm of the lever blade. A pin passes through these jaws and through
the rod, as indicated in dotted lines in that Figure, so that when the
rod is moved longitudinally back and forth the blades or floats A will
work in their fulcrums E, and open and close, as seen in Figures 1 and 2,
and move with the rod.
The sliding plate B and the blades thereon may be operated otherwise
than by the reciprocating rod C, as for instance by a vertical vibrating
lever connected with the motive power. The plate B to which the
blades are pivoted slides in grooves formed by the cleats F on the
circular stationary plate G.
H represents shoulders which strike the plate B when the blades are
at right angles with the plate, as seen in Figure 1.
The reciprocating motion of the rod C, and consequently of the
sliding plate B and blades, is indicated by the arrows. It will be seen
that the blades are thrown to a right angle with the fulcrum plate Bat
the first movement of the rod C, and that then the blades and the plate
partake of the reciprocating motion of the rod, which may be more or

page_text: less in extent. On the back stroke the blades are instantly closed, as
seen in Figure 2.
For backing the boat the blades are simply opened and closed, the
plate B being held stationary by any mechanical device provided for the
purpose.
These propellers are attached to the sides of the vessel beneath the
water line, and arranged in any manner so that a reciprocating motion
may be imparted to the short end of the blades and to the plate B.
Having described the nature of the Invention, and in what manner
the same is to be performed, I would remark that I do not confine
myself to any particulars as regards the arrangement or mode of
applying the power, nor to the particular form of any of the parts.
described; but what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,―
1st. The sliding fulcrum plate B, blades A, and reciprocating rod C,
arranged to operate substantially as and for the purposes described.
2ndly. The blade A, in combination with a reciprocating sliding
plate, when arranged to operate substantially as and for the purposes
described.
3rdly. The shoulder H of the blade, as and for the purposes
described.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Ninth day of August,
in the year of our Lord One thousand eight hundred and
seventy-two.
Witness,
JAS. O. DEWEY,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)