IMPROVEMENTS IN PROPELLING VESSELS
Year: 1853

page_text: PROVISIONAL SPECIFICATION left by the said Robert Griffiths at
the Office of the Commissioners of Patents, with his Petition, on
the 17th November 1853.
I, ROBERT GRIFFITHS, of 444, Strand, do hereby declare the nature
of the Invention for. " IMPROVEMENTS IN PROPELLING VESSELS" to be as
follows:-
This Invention relates to screw and flat blade propellers, and con-
sists of a mode of fixing such propellers to the propeller shaft: For
this purpose the boss fixed to the propeller shaft is made with sockets,
one for each propeller blade, into which sockets the shanks of the
blades are introduced. The shanks are each provided with a projection
on either side, so that when a shank has been introduced into a socket
and turned partly round, the blade will be held from coming out of the
sockets, and to retain the blades in their proper positions keys are
introduced through suitable openings in the boss, which retain and lock
the shanks in the sockets. The Invention also applies to vessels where

page_text: the propeller shaft is passed through an opening in the rudder. For
this purpose, as heretofore, the rudder is made in two parts, but
according to my improvements they are connected by a conical tubular
passage, the larger end being outwards, through which tubular passage
the case with the bearing of the propeller shaft passes, and the boss of
the propeller comes up to or partly into the conical tubular passage.
The blades of the propeller work wholly or partly within what would
ordinarily be the outer edge of the rudder, for which purpose part of
the outer edge of the rudder is removed to produce a hollow in the
rudder to receive the propeller, or in place of the rudder being in two
parts the propeller may be introduced into a recess in the front of the
rudder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Griffiths in the Great Seal Patent Office
on the 16th May 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ROBERT GRIFFITHS, of 444, Strand, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of November, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs, and succes-
sors, give and grant unto me, the said Robert Griffiths, Her special
licence that I, the said Robert Griffiths, my executors, administrators,
and assigns, or such others as I, the said Robert Griffiths, 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 Robert Griffiths, 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

page_text: 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 George Griffiths, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof (that is to say):
This Invention relates to screw and flat blade propellers, and consists
of a mode of fixing such propellers to the propeller shaft. For this
purpose the boss fixed to the propeller shaft is made with sockets, one
for each propeller blade, into which sockets the shanks of the blades are
introduced. The shanks are each provided with a projection on either
side, so that when a shank has been introduced into a socket and
turned partly round, the blade will be held from coming out of the
socket; and to retain the blades in their proper positions keys are intro-
duced through suitable openings in the boss, which retain and lock the
shanks in the sockets. The Invention also applies to vessels where the
For this
propeller shaft is passed through an opening in the rudder.
purpose, as heretofore, the rudder is made in two parts, but according
to my improvements they are connected by a conical tubular passage,
the larger end being outwards, through which tubular passage the case
with the bearing of the propeller shaft passes, and the boss of the pro-
peller comes up to or partly into the conical tubular passage. The blades
of the propeller work wholly or partly within what would ordinarily be
the outer edge of the rudder, for which purpose part of the outer edge
of the rudder is removed to produce a hollow in the rudder to receive
the propeller, or in place of the rudder being in two parts the propeller
may be introduced into a recess in the front of the rudder.
Having thus described the nature of my said Invention I will proceed
to describe the manner of performing the same.

page_text: The keys e, e
firmly into the
Figure 4, is a
The blades of the propeller having been inserted into the sockets in
the boss are kept from returning, and are adjusted to the required angle
or pitch by means of the keys a, a, which are inserted through the
openings b, b, and are pressed forward to the snugs or projections c; c
upon the propeller shank, at the same time they are prevented from
returning through the opening b, b, by the keys d, d, the length of the
keys a, a, determining the pitch or angle of the blades. The two keys
a, a, are shown of equal length, and therefore, if it be desired to vary the
pitch from that shown, then two other keys a, a, one shorter than the
other, would be introduced in place of the two shown.
are for the purpose of drawing in the propeller blades
sockets, and they act upon the tops of the snugs c; c.
section of propeller blades on line E, F; Figure 5, a section thereof
at G, H; and Figure 6, a section through I, K, of the form of propeller
blade I prefer to use, but other forms of blades may be employed if
preferred. The portions of the above sections marked-a, b, Figure 6,
are at the same angle as the section I, K, Figure 3, which is taken at
that part of the blade which makes an angle of about 45° with the
propeller shaft; the remaining parts of the blade a, c, Figure 3, and
Figure 4, being a part of a true screw, or nearly so. The action of the
propeller while in operation is to draw the water towards it at an angle
of about 45° with the propeller shaft, which is the angle of this pro-
peller blade at one third the diameter of the propeller. I therefore
make the leading edges of the blades as shown at the parts a, b, in
Figures 3, 4, and 5, and the bend a, b, is one third the width of the
blade at the point or outer end of the blade, as shown at Figure 3, at
the line E, F, a, a, b, and 'the bend come to nothing at the line I, K,
Figure 3. Figure 9, is an end' or stern view of a vessel with a propeller
applied. behind the rudder; Figure 10, a side view of the same, also
shewing an arrangement which I prefer to use for shipping and un-
shipping the propeller when at sea. a, is the propeller in its working
position; b, the propeller and shaft in course of removal. The propeller
shaft b, having been uncoupled from the engine, the chain c is attached
to it by means of the conical end to the shaft shewn in Figures 12 and
13, the shaft is then thrust back by means of a bar, and forced through

page_text: the stuffing box and tube. The pipe fis then attached, by screwing on
to the end of the stuffing box, as shewn in Figure 10, the chain c being
passed through the tube f before fastening that tube, and care is to be
observed in forming the stuffing box 'that its inner end may be readily
accessible in order to admit of the tube f being readily fixed to it. The
chain d is then slung over the propeller shaft, and the latter is thrust
entirely out of the shaft tube or after bearing, the bar by which it is
pushed out being inserted through the hole h, Figure 14, the valve i,
over which preventing the influx of water upon its removal. The
propeller and shaft is then hoisted upon deck by the chain d, the chain
c following it through the tube f: The roller g, Figure 14, is to
enable the chain c to pass freely round the curve. In order to replace
the propeller shaft the chain c is drawn.in through the tube f, and the
propeller and shaft are lowered by the chain d, until the shaft enters
the tube or outer bearing of the shaft, and it is guided and supported
by such bearing while being drawn into its place by the chain c.
Figure 7, is part of a stern view of a rudder with the conical tube for
connecting the top and bottom parts thereof, so as to allow the tubular
bracket or after bearing to come through it and support the after
end of the propeller shaft. Figure 8, is a sectional side view of the
above parts with the propeller in its place. Figure 11, is a side view
of the stern of a vessel with the propeller placed behind the stern post
and in front of the rudder, a portion of the latter being removed in order
to form an opening sufficiently large to admit the propeller, and to allow
the rudder to be moved to its extreme positions without coming into
contact with the propeller.
Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that I
make no claim to the parts separately, nor do I confine myself to the
details, but what I claim, is,
First, the combination of parts for fixing and for varying the pitch of
the propeller blades in a boss on the propeller shaft.
Secondly, I claim the combined arrangements herein described for
introducing a propeller partly or wholly into the rudder, and also the
means of connecting the parts of a rudder, and introducing a tubular

page_text: of a rudder.
In witness whereof, I, the said Robert Griffiths, have hereunto
set my hand and seal, this Thirteenth day of May, in the year
of our Lord One thousand eight hundred and fifty-four.
Witness,
B. GOBEY,
12, Cursitor Street,
Chancery Lane.
ROBT GRIFFITHS. (L.S.)