AN IMPROVEMENT IN APPARATUS FOR TAKING THE THRUST OF SCREW AND SUBMERGED PROPELLERS
Year: 1857

page_text: LETTERS PATENT to John Penn, of Greenwich, in the County of Kent,
Engineer, for the Invention of "AN IMPROVEMENT IN APPARATUS FOR
TAKING THE THRUST OF SCREW AND SUBMERGED PROPELLERS."
Sealed the 24th November 1857, and dated the 25th August 1857.
PROVISIONAL SPECIFICATION left by the said John Penn at the Office
of the Commissioners of Patents, with his Petition, on the 25th August
1857.
I, JOHN PENN, of Greenwich, in the County of Kent, Engineer, do hereby
declare the nature of the Invention for "AN IMPROVEMENT IN APPARATUS
FOR TAKING THE THRUST OF SCREW AND SUBMERGED PROPELLERS," to be as
follows:-
This Invention has for its object an improvement in apparatus for taking
the thrust of screw and submerged propellers. For this purpose a disc or
plate, (by preference made in two parts, so as readily to be fixed and removed,)
is applied between the boss of the propeller and where the propeller shaft
passes into the ship or vessel. In this plate or disc are fixed pieces of hard
wood at intervals, in such manner that the pieces of wood somewhat protrude
beyond the surface of the disc or plate. The grain of the wood may be at
right angles or otherwise to the surface of the plate or disc. The disc or
plate is made suitable for the propeller shaft to turn freely in an opening.

page_text: through its centre, and it is applied in such manner as to be held from turning
with the propeller shaft.. The forward surface of the boss or nave of the
propeller, or of a plate fixed thereto, is formed or turned truly, and is, when
the propeller is at work, constantly pressed against the projecting surfaces of
wood in the plate or disc, which is, as before mentioned, applied where the
propeller shaft passes into the vessel. The thrust of the propeller is thus
received by the pieces of wood fixed to the plate or disc, and this being
attached to the sternpost of the ship or vessel transmits to it the thrust of
the propeller, the plate or disc and wood fixed to it being immersed in the
water will be constantly well lubricated therewith.
Although it is preferred to have the pieces of wood applied to a plate
or disc capable of being readily removed, this is not essential, and, in place of
the pieces of wood being applied as above explained, they may be applied to
the boss of the propeller, or to a plate or disc fixed thereto, or to the propeller
shaft so as to revolve therewith, in which case the pieces of wood, when the
propeller is at work, will be pressed against a plate or surface formed or fixed
around where the shaft of the propeller passes into the ship or vessel; and,
although it is preferred that this apparatus should be external of the ship
or vessel, like apparatus to take the thrust of the propeller may be applied
within the ship or vessel, in which case the rubbing surfaces should be kept
well lubricated with water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Penn in the Great Seal Patent Office on the
18th February 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN PENN,
of Greenwich, in the County of Kent, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day. of August, in the year of our
Lord One thousand eight hundred and fifty-seven, in the twenty-first year
of Her reign, did,. for Herself, Her heirs, and successors, give and grant
unto me, the said John Penn, Her special licence that I, the said John
Penn, my executors, administrators, and assigns, or such others as I, the
said John Penn, 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

page_text: and Ireland, the Channel Islands, and Isle of Man, an Invention for
"AN IMPROVEMENT IN APPARATUS FOR TAKING THE THRUST OP SCREW AND SUB-
MERGED PROPELLERS," upon the condition (amongst others) that I, the said
John Penn, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, 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 John Penn, 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 has for its object an improvement in apparatus for taking
the thrust of screw and submerged propellers. For this purpose a disc or
plate (by preference made in two parts so as readily to be fixed and removed),
is applied between the boss of the propeller and where the propeller shaft
passes into the ship or vessel. In this plate or disc are fixed pieces of hard
wood at intervals, in such manner, that the pieces of wood somewhat protrude
beyond the surface of the disc or plate; the grain of the wood may be at right.
angles or otherwise to the surface of the plate or disc. The disc or plate is
made suitable for the propeller shaft to turn freely in an opening through its
centre, and it is applied in such manner as to be held from turning with the
propeller shaft. The forward surface of the boss or nave of the propeller, or
of a plate fixed thereto, is formed or turned truly, and is, when the propeller
is at work, constantly pressed against the projecting surfaces of wood in the
plate or disc, which is, as before mentioned, applied where the propeller shaft
passes into the vessel. The thrust of the propeller is thus received by the
pieces of wood fixed to the plate or disc, and this being attached to the stern-
post of the ship or vessel transmits to it the thrust of the propeller; the plate
or disc and wood fixed to it being immersed in the water will be constantly.
well lubricated therewith. .
Although it is preferred to have the pieces of wood applied to a plate or.
disc capable of being readily removed, this is not essential, and in place of the.
pieces of wood being applied as above explained they may be applied to the
boss of the propeller, or to a plate or disc fixed thereto, or to the propeller
shaft, so as to revolve therewith; in which case the pieces of wood, when the
propeller is at work, will be pressed against a plate or surface formed or fixed.
around where the shaft of the propeller passes into the ship or vessel; and,

page_text: although it is preferred that this apparatus should be external of the ship or
vessel, like apparatus to take the thrust of a propeller may be applied within
the ship or vessel, in which case the rubbing surfaces should be kept well
labricated with water.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWING.
Figure 1 shews part of a longitudinal section of the stern of a vessel,
arranged suitably for having the screw or submerged propeller raised out of the
water; Figure 2 shews a transverse section; Figure 3 shews part of a longi-
tudinal section; and Figure 4 a transverse section of apparatus, arranged for
an ordinary screw or submerged propeller; Figure 5 shews a longitudinal
section, and Figure 6 a transverse section of apparatus, when the same is
arranged internally of the ship or vessel. In each of these Figures the same
letters indicate the same parts; and I would state that when the boss of the
screw or submerged propeller is of iron, I prefer to apply or affix thereto a
ring of brass a, such as is shewn at Figure 3, suitable for working against the
wood in the part of the apparatus which takes the thrust. A is the propeller
shaft, which (in Figures 1 and 2) is at its outer end to be arranged in such
manner as to admit of the screw or propeller being separated and lifted, as is
well understood and partly shewn in Figure 1; B, in Figures 1 and 3, is the
boss of the screw or propeller; C is a plate which by preference is made in
two parts capable of going together, and of being fixed together by screws c, c,
as shewn; this disc or plate has several openings through it, in each of which
is fixed a block of hard wood D; these blocks of wood D somewhat project
beyond the surface of the plate or disc C; the plate or disc C is prevented
turning with the propeller shaft by means of fixed projections E, E; in
Figures 5 and 6 the apparatus is shewn to be arranged within the ship or
vessel; F is a trough for containing water, the bottom and also the end G of
which is made of such strength as to fit them for resisting the thrust of the
propeller. This part of the apparatus is fixed in any convenient position
intermediate of the length of the propeller shaft or shafting. In this arrange-
ment the plate or disc C is carried by the fixed plate G through which the
propeller shaft passes; the propeller shaft has affixed to it a brass surface H,
which presses against the blocks of wood D, D. This surface is made in
two parts for the convenience of its being affixed to the propeller shaft by
screws and nuts h, h, as shewn, or by other convenient means. Or, in place of
applying the apparatus intermediate of the length of the propeller shaft, the.

page_text: apparatus may be constructed in a suitable manner for being applied at
the forward end of the propeller or crank shaft, and so that such end of the
shaft may be resisted by a like arrangement of apparatus.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the details herein described, as it will be evident to an engineer that the
same may be altered in form, and in the mode of construction, without depart-
ing from the peculiarity of my Invention, which consists in constructing and
applying apparatus for taking the thrust of screw and submerged propellers
in such manner that wood may be used as herein described.
In witness whereof, I, the said John Penn, have hereunto set my
hand and seal, this Seventeenth day of February, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
CHARLES SEIDLER.
JOHN PENN. (L.S.)