IMPROVEMENTS IN CON- STRUCTING PROPELLERS FOR SHIPS AND OTHER VESSELS
Year: 1855

page_text: LETTERS PATENT to George Peacock, of Gracechurch Street, in the City
of London, Ship Owner, for the Invention of "IMPROVEMENTS IN CON-
STRUCTING PROPELLERS FOR SHIPS AND OTHER VESSELS"
PROVISIONAL SPECIFICATION left by the said George Peacock.. at the
Office of the Commissioners of Patents, with his Petition, on the
2nd January 1855. .
I, GEORGE PEACOCK, of Gracechurch Street, in the City of London, Ship
Owner, do hereby declare the nature of the Invention for "IMPROVEMENTS IN
CONSTRUCTING PROPELLERS FOR SHIPS AND OTHER VESSELS" to be as follows:-
This Invention consists of making each blade of a propeller of an open frame
of wrought iron, and covering such frame with sheet iron, by which means
great strength may be obtained with comparative lightness of structure. The
form of the propeller blades may be varied, but it is preferred that the outline
of the open frame should correspond with that of a bee's wing, and in applying
the sheet iron to such frames the same is caused to be bent or formed hollow
in front, and convex on the back surface, and to be parabolic in its curvature.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Peacock in the Great Seal Patent Office on the
2nd July 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
PEACOCK, of Gracechurch Street, in the City of London, Ship Owner, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of January, 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
George Peacock, Her special licence that I, the said George Peacock, my
executors, administrators, and assigns, or such others as I, the said George
Peacock, 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
CONSTRUCTING PROPELLERS FOR SHIPS AND OTHER VESSELS," upon the condition
(amongst others) that I, the said George Peacock, 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 per-
formed, 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 George Peacock, 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 thereof (that is to say):-
This Invention consists of making each blade of a propeller of an open frame
of wrought iron, and covering such frame with sheet iron, by which means
great strength may be obtained with comparative lightness of structure. The
form of the propeller blades may be varied, but it is preferred that the outline
of the open frame should correspond with that of a bee's wing; and in applying
the sheet iron to such frames the same is caused to bent or formed hollow
in front, and convex on the back surface, and to be parabolic in its curvature.
Having thus stated the nature of my said Invention, I will proceed to describe
the manner of performing. the same.

page_text: Figure is a starboard elevation of the propener, nuted as an auxmary ta
vessel of about 1000 tons burthen; Figure 2 is the purchase above, for raising
or lowering the propeller; Figure 3 is a plan of the purchase winch; Figure 4
is an aft elevation of the travelling carriage (m); Figure 5 is a plan of the
propeller shaft and the discs b, showing a section of the lower part of one
of the wings at C; Figures 6 and 7 are sections of one of the wings at B
and A; Figures 8 and 9 are details for fixing the feather frames a and the
bracket arms i to the discs b, and the key-holes, for securing the same to
the propeller shaft j. The propeller here shewn consists of two wings,
assimulating in form of outline of the wings of a bee, and constructed entirely
of wrought iron, in a very light, strong, and compact manner, as follows:-
What may be called two feather frames a, of plate or flat bar iron, tapering
in width to the top, are forced or shaped to the form of the wings edgeways,
the extremities being brought to a greater angle than at the discs 6, giving
an increasing spiral pitch to the wings. The ends of these feather frames a
are secured between the discs b by means of bolts and nuts, check nutted c;
ferules d are put on the bolts c, between the discs b, 'so as to keep
them at the proper distances apart on the propeller shaft j. Angle iron e
is rivetted all round the outside of the feather frames a, flush with their front
edges, to receive the surface plates "f, which are of sheet iron, of' required
thickness, according to the size of the propeller, and rivetted on to the angle,
iron'. Stout angle iron or iron may also be used for making the feather
frames in one piece, in which case the outside angle iron here mentioned would
not be required. These surface plates are dished parabolically inwards on their
faces, Figures 5, 6, and 7, so that the deepest hollow to be, say, one-tenth the
extreme breadth of the wing, which shall be at one-third from the edge that
first cuts the water when turning ahead, corresponding in effect to the hollow
in the wings of birds, particularly those of the common diver, and to the web
feet of the swan, duck, &c; but flat surfaces may also be used on these feather
frames, although the hollow parabolic surface is preferred; and the frames may
be shorter or longer, as required, according to dimensions of screw and thickness
of plate for the wings.
:
1
Back ribs or cross ties of angle iron g`and lugs g' are rivetted on to the
insides of the feather frames a across from side to side, hollowed to the form
of the parabola, and to which also the surface plates are rivetted; or the frames

page_text: .rods.o.
inay be bent, to form a facing for rivetting on the blades or wings. A stay bar
h is fastened by screw nuts and check nuts to the centre back rib of each
wing, and takes the strain of the wings when in action, going either ahead or
astern on.to the bracket arms i, which, are. bolted between the two foremost
discs.b with screw.nuts and check nuts; the whole is fixed on to the pro-
peller shaft by one or more.. keys k. This shaft is carried in the
bearings, fitted with brasses, and secured. with screw nuts and check.nuts,
the top plummer blocks of which are rivetted to the lower ends of the travelling
carriage frame.m. This carriage.runs up and down upon vertical rails
between the stern post and rudder post on sheaves n, or upon the tappet
edges of the posts themselves, and is kept home, that is, when the propeller
shaft is in position, and the bearings seated on the brackets by the moveable
The chains. r for raising and lowering the propeller are wound
upon the demi-barrels g by. the combined and reverse action of the spur
wheels r, which are. turned simultaneously by small pinions keyed on to the
spindles s, the motion being given by turning the handles t, admitting the
top of the carriage.m being raised. close up to the demi-barrels, and thereby
bringing the propeller quite out of the water.in as little space as possible when
under sail. The break u checks the. impetus in lowering. the propeller, and
the racket bites it in raising. Before lifting the propeller, the moveable
bolt w, with a long wooden shaft and handle, is introduced between the
frames of the travelling carriage. at a into the eye y, at the extremity of
the upper wing, to steady the propeller vertically in a sea-way. This bolt must
also be used when lowering the propeller into position, when it must be with-
drawn. The foremost end of. the propeller shaft j, with a tapered end, lowers
down into a clutch,z, keyed on to the end of the main shaft 2', between the
stern post..and the foremost bearing bracket 2, that receives the inner
plummer block bearing, the opening in the clutch being also tapered, so as to
ensure the T end of the propeller shaft dropping into it with facility and
certainty. The whole of the iron work is to be galvanized, the propeller shaft,
discs, bolts, stays, brackets, bracket arms, and travelling carriage separately.;
but the wings are.to.be galvanized after the facing plates are rivetted to their
places, each wing separately, ready to be bolted or keyed between the discs,
when the whole.is.keyed upon the propeller shaft and fit for action. A spare
wing can be kept on board in the event of accident, and may be easily applied
at any moment. The wings may be bent: at an angle towards the opposing
medium, like the arms or sails of a.windmill, when the opening, in the dead
wood.or.run will admit of it, or if, abaft the rudder.

page_text: Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that what I claim is, the
mode herein described of constructing propellers for ships and vessels.
In witness whereof, I, the said George Peacock, have hereunto set my
hand and seals, this Second day of July, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
W. REEVES.
GEORGE PEACOCK. (L.S.)