AN IMPROVEMENT IN STEERING PROPELLERS
Year: 1876

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent, for the Invention of" AN IMPROVEMENT IN STEERING
PROPELLERS." A communication from abroad by Frank G. Fowler, of Bridge-
port, in the County of Fairfield and State of Connecticut, United States of
America.
Sealed the 30th September 1876, and dated the 11th May 1876.
PROVISIONAL SPECIFICATION left by the said William Clark at the Office of
the Commissioners of Patents on the 11th May 1876.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "AN IMPROVEMENT IN STEERING PROPELLERS."
This Invention relates to an improvement in that class of marine propellers that
are swivelled or turned around in a horizontal plane by the steersinan, so that their
propelling force can be exerted in a direction corresponding with any point of the
compass for the purpose of steering, manoeuvring, backing, and going ahead with
vessels provided with such propellers.
The object of the Invention is to enable the steersman under such circumstances
to properly manipulate his helm. I attain this object by having an index or pointer
located in sight of the steersman, and so adjusted, geared to, and combined with
the propeller as to point out to him the direction in which the "thrust" or
propelling force is exerted. For example, if the propeller is in a position to exert
its propelling force directly ahead the index will point ahead. If the helm be
turned so that the propelling force is exerted astern the index will point astern,
and so of any point to which the propelling force can be turned the index will point
in the same direction, thus serving as an infallible guide to the steersman in turning
his helin for the purpose of steering, manoeuvring, or backing his vessel.
Having given the general nature of the Invention I will now proceed more fully
to explain its arrangeinent and operation, and in order that it may be better under-
stood I will briefly describe in detail one of the propellers to which the improvement
relates.
The blades of the propeller are pivotted to horizontal arms fixed to a vertical
shaft, each of the blades being connected by rods to the strap of an eccentric, which
is secured to the lower end of a sleeve provided at its upper end with a cog wheel,

page_text: which gears with a small wheel at the lower extremity of the shaft of the steering
wheel. As the shaft of the propeller revolves from the power of the engine the
blades are caused by the eccentric to oscillate on their pivots in such a manner as
to produce a propelling force, and the propelling force is always exerted in the
direction of the short radius of the eccentric and from the shaft. This being the
case the steersman can, by turning the eccentric by means of the helm, cast the
propelling force to any point of the compass, thus causing the boat to move forward
or backward in a direct line, or in a curved line to the right or left, or to turn in
either direction on its centre. As the propeller is submerged and hidden from
view the steersman cannot tell on starting which way the vessel will move, so there
is a constant risk of collision when there is little sea room before the direction of
the thrust of the propeller can be determined by the motion of the hull, and in
backing his boat, which is necessary in landing or docking her, he cannot tell when
the propeller is reversed. Similar difficulties occur in performing other evolutions.
These serious defects are however remedied by this Invention, and the steersman is
enabled to operate his helm so as to produce any desired manoeuvre with absolute
certainty.
The cog wheel at the upper end of the sleeve above mentioned gears into a
pinion which in turn gears into another cog wheel and a vertical spindle, to which
an index is attached. These two cog wheels have the same number of teeth, there-
fore any movement of the eccentric will be followed by a corresponding movement
of the indox in the same direction, and a revolution of the eccentric will produce a
revolution of the index. The index is set in the direction of the short radius of the
eccentric, which corresponds with the thrust of the propeller, therefore the thrust of
the propeller and direction pointed out by the index will always coincidle, and the
index will serve as an infallible guide to the steersman in the manipulation of his
helm for the purpose of manoeuvring, steering, and backing his boat, for if the helm
be turned so that the index is parallel with the keel, and points ahead, the boat
will be propelled ahead. If it makes an angle of about fifteen degrees with the
keel either to the right or left the boat will be steered to the left or right, and
with a force about equal to the maximum effect of a rudder. If it makes an angle
of more than fifteen degrees with the keel the boat will be moved in curves that
cannot be produced by the maximum effect of a rudder or any number of rudders.
If it be turned so as to make an angle of ninety degrees with the keel the vessel
will be turned on its centre, or moved sideways, depending on the location of the
propeller in the boat. If it be made to point astern the boat will be balked, and
that too without reversing the engine.
In like manner the Invention can be applied to a swivelling jet propeller, that is,
one whose nozzle can be turned around in a horizontal plane for the purpose of
steering, manoeuvring, and backing by simply gearing the indicator to the propeller
so that it will point in an opposite direction from the propeller nozzle or in the
direction of its thrust.
It can also be applied to a swivelling or steering screw propeller by gearing the
index so that it will coincide with the horizontal shaft on which the propeller
revolves, and point out the thrust of the propeller; and in like manner it can be
applied to any propeller whose thrust can be exerted to any point of the compass
by gearing the index so that it will point out the thrust of the propeller to the
steersman.
The scale which I propose to combine with the index is provided with figures or
other characters, by which a look-out nloft or officer in a distant part of the
vessel can by calling out or signalling the characters to the steersman indicate how
the vessel should be steered.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said William Clark in the Great Seal Patent Office on the 7th November
1876.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "AN IMPROVEMENT IN STEERING PROPELLERS." A communication from
abroad by Frank G. Fowler, of Bridgeport, in the County of Fairfield and State of
Connecticut, United States of America.
This Invention relates to an improvement in that class of marine propellers that
are swiveled or turned around in a horizontal plane by the steersman, so that their
propelling force can be exerted in a direction corresponding with any point of the
compass for the purpose of steering, manoeuvring, backing, and going ahead with
vessels provided with such propellers.
The object of the Invention is to enable the steersinan under such circumstances
to properly manipulate his helm. I attain this object by having an index or
pointer located in sight of the steersinan, and so adjusted, geared to, and combined
with the propeller as to point out to him the direction in which the "thrust" or
propelling force is exerted. For example, if the propeller is in a position to exert
its propelling force directly ahead the index will point ahead. If the helm be
turned so that the propelling force is exerted astern the index will point astern, and
so if any point to which the propelling force can be turned the index will point in
the same direction, thus serving as an infallible guide to the steeraman in turning
his helm for the purpose of steering, manoeuvring, or backing his boat.
Having given the general nature of the Invention I will now proceed more fully
to explain its arrangement and operation; and in order that it may be more fully
understood I will briefly describe in detail on of the propellers to which the
improvement relates.
In the accompanying Drawing Figure 1 is a sectional elevation of a propeller
consisting of feathering blades running horizontally; Figure 2 is a plan view of the
dial and pointer for showing the deviation of the thrust; Figure 3 is a plan view
of the propeller represented in Figure 1; Figure 4 is a side elevation of a screw
propeller; and Figure 5 is a side elevation of a jet propeller, all of which propellers
are swivelled for steering.
To horizontal arms a fixed to the vertical shaft H are pivoted blades D, each of
which is connected by rods b to the strap d of tho eccentric B, the latter being
secured to the lower end of the sleeve e, provided at its upper end with the cog
wheelf, into which gears a small wheel g at the lower extremity of the shaft h of
the steering wheel F. As the shaft of the propeller revolves from the power of the
engine the blades are caused by the eccentric to oscillate on their pivots in such a
marner as to produce a propelling force, and the propelling force is always exerted
in the direction of the short radius of the eccentric and from the shaft. This being
the case the steersman can by turning the eccentric by means of the helm F cast
the propelling force to any point of the compass, thus causing the vessel to move
forward or backward in a direct line, or in a curved line to the right or left, or to
turn in either direction on its centre. As the propeller is submerged and hidden
from view the steersman cannot tell on starting which way the vessel will move, so
that there is a constant risk of collision when there is little sea room before the
direction of the thrust of the propeller can be determined by the motion of the
hull, and in backing his boat, which is necessary in landing or docking her, he
cannot tell when the propeller is reversed. Similar difficulties occur in performing
other evolutions. These serious defects are however remedied by the present
Invention, and the steersman is enabled to oporate his helm so as to produce any
desired manoeuvro with absolute certainty.
The cog wheel fat the upper end of the sleeve e gears into the pinion i, which
in turn gears into the wheel J of the spindle K, to which the index A is attached
(see Figure 1). The wheels fand J havo the same number of teeth, therefore any

page_text: movement of the eccentric B will be followed by a corresponding movement of the
index A in the same direction, and a revolution of the eccentric will produce a
revolution of the index. The index is set in the direction of the short radius of
the eccentric, which corresponds with the thrust of the propeller, therefore the
thrust of the propeller and direction pointed out by the index will always coincide,
and the index will serve as an infallible guide to the steersman in the manipulation
of his helm for the purpose of manoeuvring, steering, and backing his boat, for if
the helin be turned so that the index is parallel with the keel, and points ahead,
the boat will be propelled ahead. If it makes an angle of about fifteen degrees
with the keel, either to the right or left, the boat will be steered to the left or
right, and with a force about equal to the maximum effect of a rudder. If it makes
an angle of more than fifteen degrees with the keel the boat will be moved in
curves that cannot be produced by the maximum effect of a rudder or any number
of rudders. If it be turned so as to make an angle of ninety degrees with the keel
the vessel will be turned on its centre or moved sidleways, depending on the location
of the propeller in the boat. If it be made to point astern the boat will be backed,
and that too without reversing the engine.
In like manner the Invention can be applied to a swivelling jet propeller, Figure 5,
that is, one whose nozzle N can be turned around in a horizontal plane for the
purpose of steering, manoeuvring, and backing, by simply gearing the indicator to
the propeller so that it will point in an opposite direction from the propeller nozzle,
or in the direction of its thrust, as shown.
It can also be applied to a swivelling or steering screw propeller by gearing the
index, so that it will coincide with the horizontal shaft B, on which the propeller
revolves, and point out the thrust of the propeller, as shown in Figure 4; and in
like manner it can be applied to any propeller whose thrust can be exerted to any
point of the compass by gearing the index so that it will point out the thrust of the
propeller to the steersman.
m represents a scale which I propose to combine with the index A, and provide
with figures or other characters, by which a look-out aloft or officer in a distant
part of the vessel can by calling out or signalling the characters to the steersman
indicate how the vessel should be steered.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,-
First. The index A in combination with a marine propeller whose thrust or pro-
pelling forco can be exerted in a direction corresponding with any point of the
compass in the manner and for the purpose set forth.
Second. The scale in combination with index A and a marine propeller, whoso
thrust can be exerted in any direction, substantially as set forth.
In witness whereof, I, the said William Clark, have hereunto set my hand
and seal, this Seventh day of November, in the year of our Lord One thousand
eight hundred and seventy-six.
WN. CLARK. (LS.)