IMPROVEMENTS IN HYDRAULIC PROPELLERS FOR VESSELS
Year: 1876

page_text: LETTERS PATENT to George Gilman Caldwell, of Baltimore, in the County of
Baltimore, and State of Maryland, United States of America, for the Invention
of "IMPROVEMENTS IN HYDRAULIC PROPELLERS FOR VESSELS."
186
OLL
Tw
1076
COMPLETE SPECIFICATION filed by the said George Gillman Caldwell at the
Office of the Commissioners of Patents on the 9th August 1876.
GEORGE GILMAN CALDWELL, of Baltimore, in the County of Baltimore, and
State of Maryland, United States of America. "IMPROVEMENTS IN HYDRAULIC
PROPELLERS FOR VESSELS."
In the accompanying Drawing, Figure 1 is a side view of my improved
apparatus shown as applied to a vessel; Figure 2 is a top view of the same.
Similar letters of reference indicate corresponding parts.
The present Invention relates to improvements in hydraulic propellers, and it
consists in a novel combination of elements whereby a vessel may be propelled
forward or backward, turned around or stopped, without creating a swell, as will
be herein-after more fully described.
This Invention is to be distinguished from those in which air forced against the
water in which the vessel floats is the propelling medium, as in such means there
is no reactionary force of the water ejected through the pipes; and it must also
be distinguished from those wherein water is caused to flow intermittently under
pressure through the discharge pipes, backing against a closed valve, as in my
Invention the induction and eduction pipes are during the movement of the vessel
in one direction always open, the abutment against which the streams of water
exort a pressure in producing a forward or backward movement of the vessel being
found in the air vessel of the pump employed in putting the water in motion
through the pipes.
A represents a double-acting pump; B is the connection leading to the steam
cylinder; C is the inlet or suction pipe leading to the pump A from the bottom or
side of the vessel; D is a branch inlet pipe to enable the water from leakage to be
removed by the pump A. The pipes C, D, are provided with valves E, to enable
the water to be admitted through either or neither of them as desired. From the
pump A the water is forced through the discharge pipe F or directly into the air
chamber G. From the air chamber G the water is forced out through the pipes H
•

page_text: which pass out at the stern of the vessel upon the opposite sides of and close to the
keelson and beneath and parallel with the surface of the water, and the projecting
nozzles of which are contracted. This construction will cause the water to be
discharged against the mass of the water in which the vessel floats with great
velocity, so as to produce the greatest effect. The pipes H are provided with
valves near the air chamber G, to prevent the passage of the water when the
vessel is to be stopped or backed, and with valves h³ near their outer ends, to
prevent the entrance of water should it be necessary to repair the machinery. The
valves also enable the motive power to be used for steering the vessel by closing
one of the said valves and leaving the other open. From the air chamber G two other
pipes I lead out through the bow of the vessel upon the opposite sides of and close
to the keelson. The pipes I are designed to be used for stopping and backing the
vessel, and are provided with contracted nozzles 2, and with two sets of valves **
and, in the same way and for the same purpose as the pipes H.
Having thus described my Invention, I claim as new and desire to secure by
Letters Patent,-
First. As a propeller for vessels the combination, with a double-acting force
pump, of the bow and stern water discharge pipes I, I, and H, H, having a common
inlet or suction pipe C, and provided at the points of their connection with the
pump with cocks,, and h², 2, substantially as herein described.
Second. The pipes H, H, and I, I, respectively provided with the contracted
nozzles h¹, h¹, and i¹, i¹, as and for the purposes herein described.
In testimony whereof, I have hereunto set my hand and seal, this 7th day
of July, Å.D. 1876, at Baltimore, Maryland.
Witnesses,
WILLIAM THOMPSON HOWARD,
Patent Agent,
Baltimore, Ma.
JAS. G. CUMMINS,
Br. Consular Clerk,
Baltimore.
GEORGE GILMAN CALDWELL. (L.S.)