IMPROVE- MENTS IN SCREW PROPELLERS AND IN ADJUSTING THE SAME
Year: 1857

page_text: LETTERS PATENT to Thomas Wingate, of Glasgow, in the County of
Lanark, North Britain, Engineer, for the Invention of "IMPROVEMENTS:
Scaled the 14th April 1857, and dated the 12th February 1857.
PROVISIONAL SPECIFICATION left by the said Thomas Wingate at the
Office of the Commissioners of Patents, with his Petition, on the
12th February 1857.
I, THOMAS WINGATE, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN SCREW PROPELLERS AND IN ADJUSTING THE SAME," to be as follows:-
This Invention relates to the arrangement and construction of screw pro-
pellers, for propelling ships and vessels in such manner, that, whilst the blades
or actual propelling surface portions of such screw propellers are adjustable
to any working angle with the axial line of the propelling shaft, they can-
yet be fixed firmly down in whatever position may be assigned to them whilst
the ship is afloat. Screw propellers made according to these improvements,
whilst they are easily adjustable to all the angles or working pitches required,
are quite as safe and steady in working as the best solid or immoveable,
bladed screws can be. The improvements are suited to various forms of
screws, but they are applicable to such as have large central bosses. Each.
blade is made with a very wide or thick neck, having an end central stud

page_text: I
or pin fitting a corresponding hole formed in the boss, whilst the thick part
of the neck itself is faced off to a shoulder with an inclined outer edge or
rim, accurately fitting to a corresponding recess turned in the boss. Each
neck or shoulder portion carries a toothed bevil wheel or a segment of a
wheel in gear with a central bevil wheel or segment loose on the screw
shaft; thus, in a two-bladed screw this gearing consists of three wheels or
segments of wheels, the object being to cause both blades to turn upon their
axes in concert when one is turned. In 'the interior of the large boss there
is contained a double lever arrangement, or other suitable movement, connected
with an externally projecting screw head, which can be reached from the
interior of the ship. When the screw blades are to be shifted, the operator
by means of a key or screwing rod turns the working screw of the internal
lever apparatus of the boss, when the combined action of the two levers then
lifts or forces out the two screw blades from their holding recesses in the
boss. "In this condition-the two blades are perfectly free to turn upon their
axes to any required working angle. When this is done, a clip on the lower
end of a vertical rod, which is passed down from the ship's deck above, is
made to embrace the outer end of one of the propelling blades.. The turning
of this clipping rod then obviously turns both blades to the angle required,
when both blades are again forced down into their socket recesses and secured
by the operating screw of that movement. The turning clip is now removed
and the propeller is ready for work. A deck-index is fitted up.at the top of
the vertical turning or setting rod, for the purpose of pointing out the exact
angle to which the screw blades are set after each adjustment.
SPECIFICATION in pursuance of the conditions of the Letters Patent,. filed
by the said Thomas Wingate in the Great Seal Patent Office on, the
12th August 1857. ::
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WINGATE, of Glasgow, in the 'County of Lanark, North Britain, Engineer,
send greeting.
"WHEREAS Her most Excellent Majesty Queen Victoria, by Her 'Letters
Patent, bearing date the Twelfth day of February, in the year of our Lord
One thousand eight hundred and fifty-seven, in' the twentieth year of Her reign,
did, for 'Herself, Her heirs and successors, give and grant unto me, the said
Thomas Wingate, Her special" license that 'I, the said Thomas Wingate, my
executors, administrators, and assigns, or such others as I, the said Thomas

page_text: Wingate, my executors, administrators, or 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, usc,-exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for." IMPROVEMENTS IN SCREW.
PROPELLERS AND IN ADJUSTING THE SAME," upon the condition (amongst others).
that I, the said Thomas Wingate, by an instrument in writing under my hand
and seal, 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 Thomas Wingate, do hereby declare the
nature of my said Invention, and in what manner the same is to be per
formed, to be particularly described and ascertained in and. by the following
statement in writing, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say:-
My said Invention relates to the arrangement and construction of screw,
propellers, for propelling ships and vessels in such manner, that, whilst the
blades or actual propelling surface portions of such screw propellers are
adjustable to any working angle with the axial line of the propelling, shaft,
they can yet be fixed firmly down in whatever position may be assigned to
them whilst the ship is afloat.
:
. Screw propellers made according to these improvements, whilst they are
easily adjustable to all the angles or working pitches required, are quite as
safe and steady in working as the best solid or immoveable bladed. screws
can be. The improvements are suited for various forms of screws, but they
are applicable to such as have large central bosses. Each blade is made with
a very wide or thick neck, having an end central stud. or pin fitting a
corresponding hole formed in the boss, whilst the thick part of the neck itself
is faced off to a shoulder with an inclined outer edge or rim, accurately fitting
to a corresponding recess turned in the boss. Each neck or shoulder portion
carries a toothed bevil wheel or a segment of a wheel, in gear with a central
bevil wheel or segment loose on the screw shaft; thus, in a two-bladed screw
this gearing consists of three wheels or segments of wheels, the object being
to cause both blades to turn upon their axes in concert when one is turned,
In the interior of the large boss there is contained a double lever arrangement,
or other suitable movement, connected with an externally projecting screw
head, which can be reached from the interior of the ship. When the screw
blades are to be shifted, the operator by means of a key or screwing rod

page_text: turns the working screw of the internal lever apparatus of the boss, when
the combined action of the two levers then lifts or forces out the two screw
blades from their holding recesses in the boss. In this condition the two
blades are perfectly free to turn upon their axes to any required working
angle. When this is done, a clip on the lower end of a vertical "rod, 'which
is passed down from the ship's deck above, is made to embrace the "outer
end of one of the propelling blades. The turning of this clipping rod then
obviously turns both blades to the angle required, when both blades are again
forced down into their socket recesses and secured by the operating screw
of that movement; the turning clip is now removed and the propeller is
ready for work. A deck index is fitted up at the top of the vertical turning
or setting rod, for the purpose of pointing out the exact angle to which the
screw blades are set after each adjustment.
tiff.
And in order that my said Invention may be properly understood, I shall
now proceed to describe the several illustrative Figures on the explanatory
Sheet of Drawings, which I have hereunto appended for the purpose of
showing certain modifications under which my improvements may be judiciously
carried out in practice.
Figure 1 on my Sheet of Drawings is an elevation, partially in section, of
one modification of my improved adjustable screw propeller; Figure 2 is a
partially sectional view, taken at right angles to Figure 1. Figure 3 is a plan of
the propeller; Figure 4 is a transverse section of the same. Figure 5 is an
underside view of the clip, by means of which the blades of the propeller are
adjusted, and set to any required angle, or to a plane parallel with the sides of
the vessel's keel. Figure 6 is a plan of the box-ended key for turing the
screw, which serves to actuate the mechanical arrangement, by means of
which the blades of the propeller are held fast or released, as required.
In the modification of my improvements, shown in the illustrative Sheet of
Drawings, the blades of the screw propeller are fixed in position by means of
a pair of levers, which raise the blades of the propeller out of their sockets or
force them into the same. The levers which force out the propeller blades
are actuated by means of a screw, the upper end of which is squared to
receive a key corresponding thereto; this key is lowered down on to the
squared end of the screw through an aperture made in the deck and timbers
of the ship. The screw propeller is fitted into an opening made in the timber
or iron framing at the part which is technically known as the "dead wood"
at the stern of the vessel. The driving shaft A of the propeller is carried in
bearings fitted in the uprights B, which form the sides of the opening C. The
main boss D is keyed by a transverse cotter E to the shaft A of the propeller.

page_text: The boss is of a globular form at the central part, and tapers off at each end so
as to facilitate its passage through the water. The tapering or conical portion F
at the after part of the boss D consists of a comparatively thin casing, which
serves to encase the ends of the levers which lift the propeller blades, and this
casing F also prevents the water as it is thrust aside by the central part of
the boss from closing abruptly behind it, which would tend to impede. the
speed of the vessel. The fore part G of the boss is loose upon the driving
shaft, and its edge next the central part D is made with teeth, which gear
with corresponding teeth upon the shank ends of the propeller blades. The
teeth on the edge of the part G may either be made entirely round the
circumference, or only upon parts of the periphery; in the former case
the part G forms a bevil wheel, in the latter it is a double segmental wheel.
In the modification shown in my illustrative Drawings, the teeth II on the
loose part G of the boss are made upon a portion only of its edge, as shown
in the plan, Figure 3, a corresponding number of teeth being made in the
opposite or under side of the part G. The teeth on the loose part G of the
boss gear with bevil wheels or segmental wheels made on the shank ends of
the propeller blades, so that when one of the blades is caused to turn upon
its axis it actuates the loose part G, which turns the other propeller blade
and moves it exactly in accordance with its fellow blade, but of course in the
opposite direction. The propeller blades I, at the inner part near the boss,
are made with a broad circular neck J, which is turned to a conical shape,
and fits into a corresponding recess made in the central part D of the boss.
A part of the periphery of the neck J is made with teeth, which
gear with
those on the loose part G. The plain conical portion of the neck J fits the
recessed part K of the boss, which part is accurately turned to correspond in
form to the exterior of the conical neck J. The shank L of each propeller
blade passes through a central opening in the recessed part K of the boss, and
the end of the shank is received in a cell cast in the metal of the boss where
it surrounds the driving shaft A. The central part of each shank L is turned
to form two retaining collars, which receive between them the forked ends M
of two levers N and O.
In Figure 1 of my illustrative Drawings the upper lever N is shown as
one of the first order, in which its fulcrum P is between the power and the
resistance or the propeller blade, whilst the lever O is one of the second order,
in which the resistance is between the power and the fulcrum Q. These two
levers N and O are moved in concert, but in opposite directions, by means of
a screw R, which passes through the driving shaft A, and is fast to the levers
N and O. The forked ends M of the levers N and O pass on cach side of

page_text: the central part of the shanks L of the screw propeller blades I, as is shown
in the plan, Figure 4, which is a section through the dotted line a, b, Figure 2,
of my illustrative Drawings. One end of the screw R is squared, and comes
opposite the conical or funnel shaped opening S made through the part F of
the boss. A box-ended key T is fitted to the squared end of the screw, and
this key is of sufficient length to be passed down from the deck of the vessel
through apertures made for the purpose in the deck and timbers, or plates, of
the ship. When the pitch of the screw is to be adjusted or its blades
brought into a line with the keel of the vessel, the key T is lowered down.
until its end passes into the opening S, and on to the squared end of the
screw R. The. rod of the key T is now turned round so as to cause the
screw R. to be screwed downwards. As the screw descends it carries with
it the ends of the levers N and O. The motion of the levers N and O causes
the conical parts J of the propeller blades to be partially thrust out of the
recesses K in the boss, in which they were previously wedged. The instant
the necks J of the propeller blades I are free of their seatings in the conical
recesses K, the blades I may be readily turned upon their axes and set to the
required angle, or in a plane corresponding with the head of the vessel. The
turning of the blades I is effected by means of a clip U, which slips over and
grips the edge of the upper propeller blade.
An under side view of the clip U is shown in Figure 5 of my illustrative
Sheet of Drawings. It consists of rod or shank, having at right angles to it
a T-shaped piece of metal U, which has a longitudinal groove made in it, into.
which the edge of the propeller blade is received, as shown in Figure 1. The
shank of the clip is passed through the plates or timbers of the ship up to the
deck, and in a hole in the upper end of the shank is fitted a cross bar, which
rests upon a supporting piece of metal fitted on the ship's deck. The cross
bar of the clip is supported by the rest when the clip is not in use, and it also
serves as an index to show the position of the propeller blades. For this
purpose a groove is made in the upper part of the clip rest, in which the cross
bar rests when the clip is lowered on to the edge of the propeller blade. The
position of the cross bar when the clip is on the edge of the propeller blade
at once indicates the exact angle of the blades. The propeller blades having
been released by means of the screw R, the clip is lowered on to the edge of
the upper blade; the clip is then turned by means of the cross bar until the bar
stands at the required angle. The turning of the clip causes the propeller blades
to be set at an angle corresponding to the direction of the cross bar in the shank
of the clip, the bar and the groove in the clip being in the same plane. Tho
turning of the upper blade of the propeller causes the teeth of its neck J to

page_text: actuate the loose part G of the boss, and rotate in a corresponding ratio. The
toothed part G of the boss cannot be moved without communicating the same
amount of motion to the lower blade of the propeller, for the teeth on the
lower side of the part G are in gear with those on the neck of the lower
blade; therefore the upper blade cannot be moved without actuating the lower
one in a corresponding degree. When the blades of the propeller have been
set to the required position, the screw R is screwed upwards, and the propeller
blades are allowed to rest upon their conical bearings, by which they are firmly
wedged; the key Tand the clip U are removed, and the propeller is then
entirely free.
In the operation of adjusting the propeller, the .clip U may be first
passed on t to the edge of the blade, and the propeller be thereby held
stationary whilst the key T is being passed into the aperture S, and the blades
released from their bearings. The proper propeller blade may be readily
brought into a vertical position suitable for adjustment at any moment by the
engineer 'noting (when the blade has been placed in that position for the
purpose) the position of the crank or driving wheel in relation to some fixed
object in the engine room. In this manner the propelier may at all times be
readily adjusted. The adjustment of the propeller blades may be effected by
means of wedges, screws, or wheels, in lieu of the lever arrangement, herein-
before described.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my Invention; but what
I consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,-
First, the general arrangement and construction of screw propellers,
adjustable by external means from the deck of the vessel, as herein-before
described.
Second, the system or mode of arranging and constructing screw propellers,
the blades of which are held or wedged by conical bearings, and released by
means of a lever arrangement, actuated by a screw worked from above, as
hercin-before described.
Third, the system or mode of arranging and adjusting the blades of screw
propellers by means of a clip, which also serves to indicate on deck the

page_text: exact position of the blades in relation to the head of the ship, as herein-
before described.
Fourth, the system or mode of constructing the blades of screw propellers
with conical necks, which are made to fit corresponding recesses in the boss,
as herein-before described.
Fifth, the mechanical arrangement by means of which one blade of the
propeller is caused to actuate the other in a corresponding degree, as herein-
before described.
In witness whereof, I, the said Thomas Wingate, have hereunto set my
hand and seal, this Tenth day of August, One thousand eight hundred
and fifty-seven.
THOS WINGATE. (LS.).
THOS WINGATE. (LS.).