Improvements in Propellers for Vessels.
Year: 1897

page_text: Date of Application, 14th Sept., 1897-Accepted, 23rd Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Propellers for Vessels.
I, FRANK ALEXANDER LUDWIG GRUNOW, of 2122 Clara Street, New Orleans, in
the County of Orleans and State of Louisiana, United States of America,
Mechanical Engineer, do hereby declare the nature of this invention, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
This invention relates to certain new and useful improvements in propulsion
devices for ships, and especially to a hollow drum, open at one end and closed at
the other, while in its sides are disposed a plurality of angularly-set cutter knives
or choppers between each of which is an open space through which water may
enter or be dispelled accordingly as the propelling device may be applied to the
bow or stern of the ship.
The invention further relates to a propelling device for ships, whereby for the
highest practicability, a drum, which may be of conical, cylindrical or other shape,
is carried at the bow and stern of the ship, each drum being provided with a
series of cutter knives, so arranged and operated that the forward drum, or the one
at the bow will exert a pulling force, thus producing a great speed with economic
results by a powerful suction which serves to clear the path or course in which the
ship is to travel, and break the tremendous frictional current against the bow of
the vessel, while on the stern of the ship, a similarly constructed drum, but
working in a reverse manner causes a forward pushing force, suction and
prevention of after current.
To these ends, and to such others as the invention may pertain, the same
consists further in the novel construction, combination and adaptation of the parts
as will be hereinafter more fully described and then specifically defined in the
appended claims.
I clearly illustrate my invention in the accompanying drawings which with the
letters of reference marked thereon form a part of this Specification and in which
drawings similar letters of reference indicate like parts throughout the several
views, in which:
Figure 1 is a sectional view in a vertical plane through the propelling drum
which is carried on a propelling shaft at the bow of a ship, the outline of the ship
being shown.
Figure 2 is an end view of the same drum looking into the end thereof.
Figure 3 is a detail in perspective of the propelling drum with arrows showing.
the direction of rotation of the drum and the course that the water takes in
entering the drum.
Figure 4 is a vertical, longitudinal sectional view through the stern propelling
drum showing also the stern of the vessel in outline.
Figure 5 is an end elevation of the stern propeller looking into the drum
showing the angle at which the cutter knives are set.
Reference now being had to the details of the drawings by letter, A designates
the bow of the vessel through the lower longitudinal portion of which
is carried the propelling shart B, on tne forward end...of which is
keyed the drum C. While in the drawings this drum is shown tapering and in
a conical shape, if preferred it may be cylindrical in shape if found better adapted
[Price 8d1

page_text: for the purpose. The forward end of the drum is open, and the rear end closed,
with a backwardly-extending flange C₁ which extends back and rests over a
shoulder formed in the plate D which is circular in outline and provided about its
periphery with an annular recess d.
Disposed at suitable angles to the driving shaft is a series of blades, cutters, or
choppers E, which are located at uniform intervals allowing a space F to intervene
between each. Each blade or cutter is slightly curved as best seen in Figs. 2
and 3 of the drawings, and has its longitudinal edges sharpened. The rear ends
of each blade are secured to the plate Cs and their forward ends fastened to the
ring G.
In operation, this bow propeller rotates in the direction of the inner edges of
the blades E, and in a rapid revolution the said blades E neal or slice the water
by centrifugal action, which forces the water through the horizontal channels F
between the blades outwardly and entirely out of the course of the vessel. By the
action of this displacement a suction is formed with the propeller and the supply
of water rushes through the opening at the end of the drum to fill this powerful
suction creating vacancy. By this operation the ship finds its resistance lessened
and the water is quickly forced radially out of the course of the vessel.
At the rear of the ship is mounted on the end of the propelling shaft B, a
similarly-constructed drum C but arranged to operate in a reverse manner. This
drum has the blades E, which are secured to the base C at their inner ends, their
outer ends being fastened to the ring G and disposed at an angle with space F
intervening between the edges of each blade.
The rotation of the stern propelling drum is toward the outer sharp edges of the
said blades E, which causes them to chop or slice the water by centripetal action
from the outer side inwardly, axially into the drum and after rapidly filling this
space the water rushes backward through the circular opening at the outer end of
the drum equal with the velocity at which the water enters the drum at the bow
of the vessel.
By this concentrated action, a forward pressure is produced which acts in co-
operation with a pulling force produced at the bow by which a ship may be
propelled through the water at a great velocity.
The outer circumference of the blades E, each not only takes care of the flow
of water by travel of the ship in connection with any existing stream current
against this reversed taper, but also utilizes the frictional gyration and gives
assistance in the forward pressure of motive power.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In a propelling device for ships, the combination with the propelling shaft B,
the plate D through which the shaft passes, the hub C having a convexed flange,
of the circular series of blades E secured at their rear ends to the said flange and
their forward ends fastened to a ring G, substantially as described.
2. In a propelling device for ships, the combination with the propelling shaft,
of the plate D having an annular shouldered portion d, the hub C mounted on the
shaft, the convexed flange C¹, the outer circumference of the edge of which is
designed to travel about the shoulder on plate D, and the curved blades E,
arranged substantially as shown and described.
Dated this 14th day of September 1807
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W. C., Agents.