IMPROVEMENTS IN APPARATUS FOR PROPELLINO VESSELS
Year: 1879

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 PROPELLINO VESSELS." A communication from abroad by
Jean Louis Nevers, of Pass Christian, in the County of Harrison, State of
Mississinni. United States of America.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 9th June 1879.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS." [A
communication from abroad by Jean Louis Nevers, of Pass Christian, in the County
of Harrison, State of Mississippi, United States of America.]
The object of this Invention is to provide a simple, adjustable, and powerful
propeller, by which a vessel inay be made to go forward or backward, or to turn
readily in any direction.
The propeller consists of two twin blades vertically hinged to an upright shaft
adjustable for forward or backward pressure upon the water at each stroke,
whose operating motion is a backward and forward reciprocating one in a line
parallel with the keel of the vessel. The shaft to which the blades are secured
passes through and is secured to and vertically adjustable in a head block on the
end of a rod connected with the driving mechanism. This shaft may be raised or
lowered at will to any position, and held by means of a set screw. The lower
portion of the shaft is round and has a square shoulder, on which a disc or wheel
of oval cross section is adjustably secured. This disc has shouldered faces, said
shoulders running at right angles to the connecting rod. Hinged on the lower part
of the shaft, and kept in position by suitable collars, are the rectangular propeller
blades that are cut away at their centres to fit over and conform to the disc. To
the upper end of the shaft a forked head piece is rigidly secured. This head piece
has four upwardly projecting lugs, through the two rearmost of which passes a
horizontal crank shaft supporting between the lugs a forked cam. A lever is
pivoted between the two forward lugs, one end of which rests in the fork of the
cam, while the other is attached to an adjusting rod that extends downward through
D

page_text: the head block on the connecting rod, and is connected at its lower end with the
disc. The handle of the crank shaft is held in position while the mechanism is in
operation by a notched or toothed spring. Upon the stern rail of the boat on either
side of the stern post are secured standards carrying vertically adjustable blocks,
and on one side of each block is a V shaped cam, and on the other side a handle,
which are held in position and connected with each other by a pin that passes hori-
zontally through the block. Within the boat in suitable position is the driving
mechanism, which may consist of an engine of any style suited to the work, and
this engine causes the connecting rods to move with a horizontal and reciprocating
movement, so that the propellers that are suspended at right angles from them shall
be moved back and forward in lines parallel with the keel of the boat.
When it is desired to propel the boat forward the elevation of the crank handle
causes the forked cam to lift the free end of the lever and depress the rod, to which
is secured the disc, so that said disc shall be passed down to its lowest limit. During
this operation the propeller blades are set back, and when a forward motion is given
to the propellers the blades will be swung back by the resistance of the water
against a pin, which prevents their contact with each other, while on the reverse
stroke the blades will spread and hold at right angles to the line of direction, and
force against the shoulders on the disc, and thus give a forward movement to the
boat.
When it is desired to move the boat astern the adjusting rod is elevated by the
crank handle and the disc raised to its extreme limit, so that its upper shoulders
shall oppose resistance to the backward folding of the blades, and hold them spread
open on the forward motion of the propeller. Thus the motion of the propeller
blades and the consequent motion of the boat can be reversed at any moment
without reversal of the engine, and it is evident that the boat can be quickly turned
by arranging one propeller so that it will tend to pull the boat astern, while the
other tends to impel it forward. When the device is in operation the blocks on the
standards are so adjusted that the jaws of the cams shall be on a level with the
crank handles of the crank shafts, and the cam is held, when it is not desirable to
change the direction of the propeller blades, so that the crank handles may in their
backward and forward movements enter the jaws without coming in contact with
them, but should it become desirable to change the direction of the blades, the cams
are adjusted in such a manner that the handles of the cranks will, on the next
forward stroke, engage against the inner slopes of the upper or lower jaws, as the
case may be, and cause the consequent elevation or depression of the discs and the
desired change in the position and effect of the blades.
Thus it will be seen that the change of direction is always under the immediate
control of the person who has charge of the devices that are set inboard near the
steering wheel, and that though the motion of the engine may not cease, the positions
of the blades can readily be so changed at each stroke that they will exert no force
upon the water.
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 8th
December 1879.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS." A
communication from abroad by Jean Louis Nevers, of Pass Christian, in the County
of Harrison, State of Mississippi, United States of America.
The object of this Invention is to provide a simple, adjustable, and most powerful
propeller, by which a boat may be made to go forward or backward, or to turn

page_text: readily in any direction. In the accompanying Drawings, Figure 1 is a plan view,
showing the propeller attached to the boat; Figure 2 is a side elevation of the same;
Figure 3 is a side elevation of one propeller complete with its working parts;
Figure 4 is an elevation of the vertical shaft; Figure 5 is a plan of the wheel or
disc that limits and controls the movements of the propeller blades; Figure 6 is a
transverse section of the same on line y-y. Similar letters of referenco indicate
corresponding parts. The Invention consists of the shaft A depending perpendicu-
larly down through, and secured and vertically adjustable in the head block S on
the end of the connecting rod T. This shaft may be raised or lowered at will to
any position, and so held by turning the set screw a' against its square section in
the block S.
The lower portion of the shaft is round, and carries vertically adjustable upon
its square shoulder b¹ the disc or wheel B of oval cross section and ridged or
shouldered faces, said shoulders running across the faces at right angles to the
connecting rod.
Hinged on the lower part of the shaft, and kept in position by the collars c', c³,
are the rectangular propeller blades C, C, that are cut away at their centres to fit
over and conform to the wheel B.
The forked head piece D that is rigidly secured to the upper end of the shaft A
has four upwardly projecting lugs d', d, through the two rearmost of which the hori-
zontal crank shaft f' passes, supporting between the lugs the forked cam E. Pivoted
between the two forward lugs is the lever F, one end of which rests in the fork of
the cam E, while the other is attached to the adjusting rod G that extends down-
ward through the head block S, and is connected at its lower end with the disc or
wheel B. H represents a notched or toothed spring, whose function is to hold the
handle of the crank shaft f' in position while the mechanism is in operation.
Secured upon the stern rail of the boat I, on either sides of the stern post, are
the two standards K, K, on which are held by set screws or other equivalent device
the vertically adjustable blocks L, L. On one side of each block is a V shaped cam
M, and on the other side a handle N, which are held in position and connected with
each other by the piu g¹ that passes horizontally through the block.
Within the boat in suitable position is the driving mechanism O, which may
consist of an engine of any style suited to the work, and this engine causes the
connecting rods to move with a horizontal and reciprocating movement, so that the
propellers that are suspended at right angles from them shall be moved back and
forward in lines parallel with the keel of the boat.
When it is desired to propel the boat forward the elevation of the crank handle
f1 causes the forked cam E to lift the free end of the lever Fand depress the rod G,
to which is secured the wheel B, so that said wheel shall be passed down to the
lowest limit of its range. During this operation the propeller blades C, C, are set
back, as shown in the case of the port propeller, Figure 1; then when a forward
motion is given to the propellers the blades will be swung back by the resistance of
the water to the position shown in port propeller, Figure 2, against the pin k, which
prevents their contact with each other, while on the reverse stroke the blades will
spread and hold at right angles to the line of direction and force against the lower
shoulders h¹, h¹ of the wheels B, B, and thus give a forward movement to the
boat.
When it is desired to move the boat astern, the rod G is elevated by means of
the crank handle f¹ and the wheel B raised to its extreme limit, so that the upper
shoulders l', ', shall oppose resistance to the backward folding of the blades, and
hold them spread open on the forward motion of the propeller. Thus it will be
seen that the motion of the propeller blades and the consequent motion of the boat
can be reversed at any moment without reversal of the engine. And it is evident
that the boat can be quickly turned by arranging one propeller so that it will tend
to pull the boat astern while the other tends to impel it forward.
When the device is in operation the blocks L, L, are adjusted on the standards
K, K, so that the jaws of the cams M, M, shall be on a level with the handles f¹, ƒ¹,

page_text: of the crank shafts, and the cam is held in about the position shown in Figure 2,
when it is not desirable to change the direction of the propeller blades, so that the
handles f¹, f, may in their backward and forward movements enter the jaws
without coming in contact with them. But should it become desirable to change
the direction of the blades, the cams are adjusted by the handles N, N, in such a
manner, inclined upward or downward, that the handles f, f, of the cranks will
on the next forward stroke engage against the inner slopes of the upper or lower
jaws, as the case may be, and cause the consequent elevation or depression of the
wheels B and the desired change in the position and effect of the blades.
Thus it will be seen that the change of direction is always under the immediate
control of the person who has charge of the devices that are set in board near the
steering wheel, and that though the motion of the engine may not cease, the posi-
tions of the blades can readily be so changed at each stroke that they will exert no
force upon the water.
The propeller blades need not necessarily be rectangular in outline as herein
shown, nor do I confine myself to the precise construction of parts as shown in the
Drawings, as I have purposed in this to exhibit the device and its working parts in
the most simple form rather than in the precise manner in which it would be appli
cable to a vessel.
It must be obvious that it is of great advantage to be able, as herein shown, to
raise or lower the propeller blades, so as to make them equally effective in a heavy
sca and shallow water, and to adjust them at will to suit the changing draft of the
vessel.
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,-
1st. The combination of the perpendicular shaft A, head block S, connecting rod
T, wheel B, collars c', c', and propeller blades C, C, substantially as herein shown
and described.
2nd. The combination of forked head piece D, provided with lugs d', d², crank
shaft, cam E, lever F, rod G, and spring H, with the wheel B, and propeller
blades C, C, substantially as and for the purpose described.
3rd. The combination of the standard K, block L, cam M, handle N, and pin g',
with crank shaft f¹, rod G, and propeller blades C, C, substantially as herein shown
and described.
4th. A vessel's propeller, consisting of two twin blades vertically hinged to an
upright shaft adjustable for forward or backward pressure upon the water at cach
stroke, whose operating motion is a backward and forward reciprocating one on a line
parallel with the keel of the vessel, substantially as herein shown and described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Eighth day of December, in the year of our Lord
One thousand eight hundred and seventy nine.
A. M. CLARK (L.S.)