IMPROVEMENTS IN PROPELLING VESSELS
Year: 1855

page_text: LETTERS PATENT to William Craymer, of Bristol, in the County of
Gloucester, Carver, for the Invention of "IMPROVEMENTS IN PROPELLING
VESSELS."
Sealed the 4th March 1856, and dated the 5th September 1855.
PROVISIONAL SPECIFICATION left by the said William Craymer at the
Office of the Commissioners of Patents, with his Petition, on the 5th
September 1855.
I, WILLIAM CRAYMER, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN PROPELLING VESSELS" to be as follows:-
It is well known to be very desirable for ships or other vessels propelled by
what is commonly called the screw propeller, that some means should be found
for placing the blades of the screw in other than a fixed position. The terni
used for explaining what is required or desired is, I believe, "feathering the
screw." Many attempts have been made with more or less success, but none
of the contrivances for that purpose hitherto submitted to the public have met
with such success as to cause their general or even partial adoption. I propose
to arrange the blades of the screw in the following manner:-And, first, I
would say, that it is my intention to cast the metal blades or float with a slot
across its plain about one-third of the distance from its connexion with the boss
or nave and its outer extremity. From the boss or nave (on which the floats

page_text: are fixed, not cast) three or more spokes (cast with the boss, unless it be found
more desirable to make them separate, and affix them thereto,) project in such
manner as to allow a metal hoop or band to pass through the slots in the
floats, and then to be firmly attached to the extremities of the said spokes.
When this is done, the whole will have the appearance of a wheel with
projections on its outer periphery. Under and attached to each float will
be a metal quadrant, and between each slot will be fitted with a pivot passing
through the wheel aforesaid, and permitting the float to turn edgeways or
feather.
These quadrants (or quadrant-shaped) will have cogs or teeth cut into the
segmental part thereof, and thus communicate or gear into a cogged radiated
wheel. A rod or shaft passes horizontally from the back of this wheel, to which
it will be secured up to any distance in the interior or hold of the vessel; but
on it will be fixed another quadrant-shaped piece of metal having teeth or cogs
similar to those mentioned as placed under or attached to the floats.
Attached to the shaft framing will be an helical apparatus, (capable of being
worked by a boy); this on being turned by a key or handle will communicate
motion (right or left as desired) to the quadrant on the shaft, thence to the
cogged wheel, so on to the float quadrants, and finally to the floats themselves,
which may thus be placed or fixed at any angle required, such angle being
altered at pleasure. But as the whole of the apparatus may be found some-
what expensive, I propose, as in the case of colliers or other vessels, when it
may be desirable to study economy in the fitting up, to pass a wheel as broad
or narrow as may be found desirable over the outer extremities of the floats or
blades of the screw, (I anticipate using three blades, but more may be used, if
desired;) one end of the float will be secured in the boss or nave, either by
being cast therewith or otherwise. There will also be three spokes or supports
to the band, which I anticipate will add to rather than diminish the force of
the propelling power; these, [as before mentioned, are secured in any way
to the boss or nave, and to the band.
The said band will be pierced with holes, each hole corresponding with the
outer end of the float or blade, on which at its centre will be placed a piece
destined to hold it firmly, so that a pivot made thereon and passing through the
hole in the band aforesaid may be allowed to work. Combined with this pivot
are a pair of small wheels, the faces of each being cut into corresponding rugs
of cogs or teeth. These are so arranged as to be worked upon from the deck
of the vessel, as thus :-A casing is made through the stern, so that a spanner
may pass through, and as each end of the float presents itself it may be wound
to a corresponding angle, and so the whole will be feathered. With the

page_text: arrangement first described, I propose to use a float or blade with its end
fashioned like a scoop, but having in its area an apperture, behind which is to
be a back; the use of the latter being to prevent the too sudden escape of
the water when it shall have been acted upon by the scooped blade, but still
to allow of its easy passage, so that the extra hold obtained on the water by
the peculiar form of the screw blade shall not endanger the safety of the
blade itself.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Craymer in the Great Seal Patent Office on the
5th March 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CRAYMER, of Bristol, in the County of Gloucester, Carver, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of September, One thousand eight
hundred and fifty-five, in the nineteenth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said
William Craymer, Her special license that I, the said William Craymer,
my executors, administrators, and assigns, or such others as I, the said
William Craymer, 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 Craymer, 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 William Craymer, 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 Drawing hereunto annexed and forming
part of this my Specification, and to the letters of reference placed thereon,
similar letters being used to denote similar parts (where such parts can be seen
in each of the Diagrams respectively) :-

page_text: In propelling ships or other vessels by steam or other power, acting on a
screw propeller, it is often desirable to change the position of the floats or blades
of the screw in order to add to the propelling power thereof, and avoid the
"back water" or hold of water upon the floats, when they should pass freely
after making the propelling stroke; also for other purposes, such as facili-
tating the clearance of the screw or floats from "hamper," sea weed, or other
obstructions. I am aware many plans have been proposed for this purpose,
some forming the subject of Letters Patent; amongst the latter I find that of
Mr. William Hewitt, No. 1364, for "Improvements in Propelling Vessels,"
dated the 15th day of June 1855; and herein, at first sight, a similarity to my
Invention will be perceived. He uses quadrant-shaped cogged pieces to gear
into other parts of apparatus; and in one of the modifications of my Invention I
use similar pieces, but not only in different positions, but for different purposes.
I therefore believe that the modes of "feathering the screw
herein-after
described, will be found to be essentially new, and to answer the purposes for
which they are intended better than any hitherto employed.
In the Drawing, Figure 1 shews a side view of the main propelling shaft
and floats; Figure 2 is an end view of the same; Figure 3, a front view of
three floats fixed in band, according to second modification; Figure 4, front
view of "scoop" float; Figure 5, section of same at A, B; and Figure 6 shews
section of hollow shaft.
At Figure 1 it will be seen that a hollow shaft a is used, within which is
another shaft b, shorter than a. On this short shaft at one end is fixed a
quadrant-shaped rack c, with an endless screw d, working therein; and at
the other end of this shaft is shewn another quadrant-shaped toothed piece
e fixed thereto. There is also on the bottom of each float fixed a quadrant-
shaped toothed piece, the purpose of which will be hereafter described.
The bottom or thick end of each float is provided with a strong pin let into
the boss on the shaft; from this boss projects two or more spokes g, and
on the outer end of the spokes is placed a ring h, which passes through
holes made in the floats; a pin i is fixed to the floats and passes through the
ring h, so that as the floats are turned or feathered the pins in the boss and in
the ring act as centres for the feathering of the floats. The modus operandi is
as follows:-The endless screw d is provided with a crank handle, which on
being turned imparts motion first to the quadrant-shaped rack c, from thence
to the shaft, so on to the quadrant-shaped piece e, which gearing into the
toothed pieces on the floats move simultaneously.
At Figure 3 will be seen, another method of feathering the floats. Three
or more floats are placed on the boss of the main shaft, working therein on

page_text: pins, and pins are also fixed at the other end of each float, and pass through
a stout circular band or hoop. The end of each outer pin is formed square,
for the purpose of a key or spanner being passed through a hole to be made
in the deck, and on to the square or other shaped pins, which can then be
turned to feather the floats to the required angle as the upper part of each
float presents itself under the hole aforesaid.
+
At Figures 4 and 5 a different form of float is shewn, which float or blade
is made somewhat in the form of a scoop. In the blade of the float is made
an aperture of any desired size, but on the back of the float is fixed or cast
a flap; this is for the purpose of preventing the escape of the water before
it has supplied the fullest resisting medium for propelling. It will be observed
that a ring passes through the floats or blades; in order to permit this, a slot
of adequate opening must be left in the blade at its casting about one-third of
the distance from its connection with the boss or nave and its outer extremity.
The spokes are either cast on the boss or made seperately, and screwed or
otherwise fixed therein; and on the ends of these spokes the metal ring h,
herein-before mentioned, is securely fixed in any practicable manner; and on
the outer periphery of this ring the floats or blades are placed and acted upon
in the manner herein-before described, and shewn in the Diagrams. The whole
of the parts can be made of whatever metal may be found most serviceable for
the various purposes herein mentioned. In Figure 3 I have shewn three floats
or blades, but a greater or lesser number may be used, as may be found most
serviceable.
By the foregoing description I have fully explained the means by which I
carry my Invention into practical effect, reference being had, as before
mentioned, to the accompanying Drawing; but I would have it distinctly
understood that I lay no claim to the exclusive use of any of the particular or
seperate parts or portions of machinery or apparatus herein-before described
or shewn in the Drawing, taken seperately as parts or portions, and not in
combination, for the purposes of my Invention; nor do I confine myself to the
exact relative proportions of parts to each other, as shewn in the Drawing, as
such may be varied and altered to suit vessels of different description or power,
and such varying proportions can be made without at all departing from the
principle of my Invention; but I do claim,-
Firstly, the exclusive use of the combination of parts shewn at Figures 1
and 2, and herein-before described, forming when so combined a new means
or apparatus for turning the blades or floats of the screw commonly called
feathering the screw."
Secondly, I claim the exclusive use of the combination of parts herein-before

page_text: described, and partly shewn at Figure 3, forming when so combined a new
means or apparatus for feathering the screw.
Thirdly, the peculiar scoop float or blade for the screw, herein-before
described, and shewn at Figures 4 and 5 of the Drawing.
In witness whereof, I, the said William Craymer, have hereunto affixed
my hand and seal, this Fourth day of March, in the year of our Lord
One thousand eight hundred and fifty-six.
Witness,
SOLOMON FRY,
1, Quay Street, Bristol.
WILLIAM CRAYMER. (L.S.)