IMPROVEMENTS IN PROPELLING VESSELS
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by the said William Hewitt at the
Office of the Commissioners of Patents, with his Petition, on the 15th
June 1855.
I, WILLIAM HEWITT, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN PROPELLING VESSELS". to be as follows:-
I propose by my Invention (amongst other minor advantages) to regulate the
action and force of the floats or blades used in those vessels, called "screws,"
so that the maximum or minimum force. or. resistance may be applied or
offered to the sea by such floats- as the state, of the ocean may require. I
propose by my arrangements to render, unnecessary the "well," or space
allotted in screw steamers for raising the screw, as I anticipate being able to
render such space unnecessary to the purpose for which it is now applied, and
so save it for general uses. In effecting these objects, I propose to, use a
double wheel (say, with outer-and-inner-rings), the inner circle of which will
be attached to a moveable casing (on which the wheel and floats, or blade
work); this casing or cylinder will revolve upon a fixed shaft. I intend t

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arrange the floats between the casing and the outer circle of the wheel, and in
such manner as they shall be diagonally, (say, at an angle of 45 degrees,) but
the floats or blades will be so arranged as to permit their being feathered
or fixed at any angle required, or fixed vertically, should it desirable
and these alterations will be effected without taking up the screw by the
means to be provided by the mechanical arrangements I intend to employ for
this purpose. My improvements are entirely independant of the nature of
the propelling power, whether such power be steam or any other.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Hewitt in the Great Seal Patent Office on the
13th December 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HEWITT, of Bristol, in the County of Somerset, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of June, in the year of our Lord One
thousand eight hundred and fifty-five, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Hewitt, Her especial license that I, the said William Hewitt, my
executors, administrators, and assigns, or such others as I, the said William
Hewitt, my executors, administrators, and 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, use, exercise, and
vend; within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PROPELLING
VESSELS," upon the condition (amongst others) that I, the said William
Hewitt, by an instrument in writing under my land and seal, should par-
ticularly 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 William Hewitt, do hereby declare the
nature of the 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, reference being had to the accompanying Sheet of Drawings, form-
ing part of this my Specification, and to the letters of reference marked

page_text: thereon, denoting similar parts where such parts appear or can be seen in each
of the Figures respectively:
It is needless to dwell upon the fact that a successful mode of altering
the positions of the fan, float, or blade of the screw propeller (called
5 feathering the screw), whether the screw be under water or not, is of con-
siderable importance to navigation. Many attempts have been made to effect
this object with more or less success, but in no case has it been, I believe,
entirely achieved, and the want of an efficient contrivance is still felt in the
screw steam marine.
)-
In the accompanying Drawing, Figure 1 represents a side elevation of the
end portion of the shaft, having thereon the apparatus of wheels, fans,
floats, or blades, as the whole would appear when ready for use; Figure 2
represents a longitudinal section (or part in section), of the whole apparatus
used in my Invention, and fitted together for propelling; Figure 3 is a front.
view of a male clutch; Figure 4, a vertical section thereof; Figure 5 gives
a face or front view of a female clutch, with cuts or grooves made therein,
and marked by degrees, each of which cuts, grooves, or indentations are made
so as to receive the projection on the male clutch, as it may be found desirable
to use them in altering the position of the screw blades; Figure 6 shows a
lever attached to coupling brasses, such lever serving to connect or disconnect.
the male and female clutches before mentioned; Figure 7 is a plan view of a
rack and pinion, the use of which is to put the bevilled wheels in or out of
gear with the quadrants; Figure 8 denotes a key serving to withdraw the
fans or blades from the boss when such operation is required; and Figure 9 is
a key of a different description, to be used for replacing the floats or blades into
the boss or nave of the screw head. The whole of the above parts may be
made of any metal or material suitable for the purpose, and combining
strength, with comparative lightness of material and economy of cost.
a
I will now proceed to describe the putting together of the several parts of
my improvements. On reference to Figure 2, it will be seen that denotes the
main shaft of the propeller, on the end of which is fitted a boss or nave b; or
the boss may be welded thereon if desired, and according to the nature of the
metal used; or otherwise constructed, as may be most expedient. Encasing:
this shaft in a portion of its length is a cylinder or tube c, of strength pro-
portionate to withstand the lateral shocks to which a screw-propelling apparatus
is always liable. On that end of this casing nearest the stern of the vessel
is adjusted and secured a bevilled wheel d, the cogs of which wheel work or
gear into those of two quadrant-shaped racks e, e; these racks or quadrants
are firmly secured to the floats, fans, or blades f.f, in the position shewn in.

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the Drawing at both Figures 1 and 2 thereon. Again, at this Figure 2 may
be observed a rack and pinion marked g, which are fixed to the outer casing
or tube c; the use to which the rack and pinion is applied is to put the bevilled
wheel & in or out of gear with the quadrant-shaped racks above described, e, e.
The tube or casing c is moved (over the main shaft) in a rotary direction or 5
motion by means of the wheel h; fixed or attached to the female clutch on the
said casing, with the assistance of a pinion i working without the casing. By
particular reference to Figure 1, it will be seen that by means of this pinion i
acting, as aforesaid, that the blades, floats, or fans can be moved, set, or
feathered to any required angle, the quadrants being placed on the floats or
blades in such manner in the Drawing, that if they were working in the water
little or no resistance would be made to their stroke thereon or therein; but
when the opposite ends of the quadrants e, e, commence to gear or work into
the wheel d, the feathering and consequent impingement on the water and
resistance of the latter commences. To effect this, or, in other words; to
obtain the propelling power, it is requisite to turn the pinion. i by a handle, as
shewn; this imparts motion to the tube or casing, from thence to the wheel d,
which acts on the quadrant-shaped racks affixed to the screw blades, as afore-
said, and by this operation the fans, floats, or blades which are screwed into
the boss or nave bare acted upon, and can be moved in either direction, left
or right. The screw blades being immersed in the water would render it
difficult to ascertain at what angle they might be working at any given time;
but to provide against this uncertainty, a female clutch j, Figure 5, is fixed
on to the side of the wheel attached to the tube c, with cuts or grooves
(as before described) cut round the face of it, and numbered with the different
degrees requisite for the working of the screw, fans, or blades: A male-
clutch provided with a tongue across its surface is made to traverse on the
main shaft, and when the fans or blades are feathered or set to the required
angle the male clutch K is forced forward by means of a lever (Figure 6),
and into whichever cavity or groove it is intended to be fixed, the shaft being
then set in motion, the propelling power is obtained. I may here observe
that the clutches, racks, and pinnions are all within the engine room of the
ship, and consequently under the immediate control of the engineer. In case
of accident to one or other of the fans or blades, rendering its removal neces-
sary or desirable; I have made the following provision for that purpose:-
On each side of the blade, float, or fan is fixed a left-handed screw worn
(m, Figure 1) a left-handed long screw key (Figure 8) is made to fit the
worm m, and on the screw of the said key being inserted into the worm m,
and turned to the left, the blade will be unscrewed out of the boss, and can

page_text: be taken in-board. Previous to this operation care should be taken to draw
the tube or casing c back, so as to throw the wheel d out of gear with the
quadrants e, e, on the blades. To replace or renew a float or blade, it should
be let down into its place by means of the key, Figure 8; and another key,
Figure 9, dropped into the top or end of the float or blade and turned to the
right hand, which will screw the fan or blade into the boss, and at the same
time release the fan from the screw key.
Having now described the nature of my Invention, and the means by
which I carry it into practical effect, I desire it to be distinctly understood
that I lay no claim to the exclusive use of any of the parts or portions of
machinery. or apparatus I have herein described or shewn in the Drawing,
taken as parts or portions, or when used seperately and not in combination
for the purpose of my Invention; nor do I confine myself to the exact
modifications herein described, nor to the proportion of parts to each other, as
such may, and indeed must be, varied to suit various ships or vessels; but I
declare to be of my Invention, and I claim, the exclusive use of the com-
bination of parts or portions of machinery or apparatus herein-before described
and shewn, which form when so combined an improved means of propelling
vessels.
In witness whereof, I, the said William Hewitt, have hereunto set my
hand and seal, this Twelfth day of December, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
HENRY NEWMAN,
Nicholas Street, Bristol.
WILLIAM HEWITT. (L.S.)