IMPROVEMENTS IN PROPELLING AND STEERING APPARATUS FOR SHIPS OR VESSELS
Year: 1881

page_text: LETTERS PATENT to John Isaac Thornycroft, of the Firm of John I. Thornycroft
and Co., of Church Wharf, Chiswick, in the County of Middlesex, Steam
Yacht and Launch Builders, for an Invention of "IMPROVEMENTS
IN
PROVISIONAL SPECIFICATION left by the said John Isaac Thornycroft at
the Office of the Commissioners of Patents on the 29th April 1881.
JOHN ISAAC THORNYCROFT, of the Firm of John I. Thornycroft and Co., of
Church Wharf, Chiswick, in the County of Middlesex, Steam Yacht and Launch
Builders. "IMPROVEMENTS IN PROPELLING AND STEERING APPARATUS FOR SHIPS
OR VESSELS."
In the Specification of Letters Patent granted to me the 3rd April, A.D. 1879
(No. 1330), is described the use in apparatus for propelling and steering ships or
vessels of a propeller, having behind it and arranged in line with its boss a boby
having a gradually increasing diameter or width for a short distance, and afterwards
a gradually diminishing diameter or width to its rearward end.
This body, which I will call the rearward body, is furnished with guide plates or
blades for gradually deflecting and directing the water projected from the propeller
into a direction approximately parallel with the body axis. Around the propeller
and body behind it is a pipe, tube, case, or hollow guide.
Now in such apparatus according to my present Invention I make the rearward
body in two parts or lengths (or there may be more), and the rearward part or
length (or parts or lengths) I pivot, so that it (or they) may be moved to port or to
starboard after the manner of a rudder.
In one arrangement I combine such moveable portion of the rearward body with
a rudder, thus forming in rear of the propeller a combined water guide and steering
apparatus.
The surrounding pipe, tube, case, or hollow guide may terminate at or near the
point of junction of the fixed and moveable parts of the rearward body, and in
some cases I provide at the respective sides of the pipe, tube, case, or hollow guide
curved plates or guides able to turn on suitable pins and to be operated from the
tiller. In front of the pipe, tube, case, or hollow guide I provide a grid or guard
to prevent fouling of the apparatus by floating or other matters.
As is obvious various arrangements of apparatus may be constructed to operate
on the principle of my Invention, as hereinabove set forth.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Isaac Thornycroft in the Great Seal Patent Office on the
29th October 1881.
JOHN ISAAC THORNYCROFT, of the Firm of John I. Thornycroft and Co., of
Church Wharf, Chiswick, in the County of Middlesex, Steam Yacht and Launch
Builders. "IMPROVEMENTS IN PROPELLING AND STEERING APPARATUS FOR SHIPS
OR VESSELS."
In the Specification of Letters Patent granted to me the 3rd April, A.D. 1879
(No. 1330), is described the use in apparatus for propelling and steering ships or
vessels of a propeller having behind it and arranged in line with its boss a body
having a gradually increasing diameter or width for a short distance, and afterwards
a gradually diminishing diameter or width to its rearward end. This body, which
I will call the rearward body, is furnished with guide plates or blades for gradually
deflecting and directing the water projected from the propeller into a direction
approximately parallel with the body axis. Around the propeller and body
behind it is a pipe, tube, case, or hollow guide.
Now in such apparatus according to my present Invention I make the rearward
body in two parts or lengths (or there may be more), and the rearward part or
length (or parts or lengths) I pivot, so that it (or they) may be moved to port or to
starboard after the manner of a rudder.
In one arrangement I combine such moveable portion of the rearward body with
a rudder, thus forming in rear of the propeller a combined water guide and steering
apparatus.
The surrounding pipe, tube, case, or hollow guide may terminate at or near the
point of junction of the fixed and moveable parts of the rearward body, and in some
cases I provide at the respective sides of the pipe, tube, case, or hollow guide curved
plates or guides able to turn on suitable pins and to be operated from the tiller.
In front of the pipe, tube, case, or hollow guide I provide a grid or guard to
prevent fouling of the apparatus by floating or other matters.
As is obvious various arrangements of apparatus may be constructed to operate
on the principle of my Invention, as hereinabove set forth.
Referring to the accompanying three Sheets of Drawings, Fig. 1 is a central
vertical longitudinal sectional elevation of the stern portion of a vessel provided
with steering and propelling apparatus according to my Invention; Fig. 2 is an end
elevation partly in section; and Fig. 3 is a plan of the same.
Behind the propeller 1 is the rearward body formed in two parts 2a and 2b,
whereof 2 is of a gradually increasing diameter or width as it proceeds backwards,
and 2b is of a gradually diminishing diameter or width to its rearward end. The
part 2b is combined with the rudder 5, and is centred or pivotted together with the
rudder on the stud or pintle 6 attached to the stem frame 7, the two being operated
together by the rudder head or axis 8 and the tiller 9, and being simultaneously
put over towards port or starboard when the tiller is moved for the purpose of
steering. The forward end of the part 2b is of a spherical or spheroidal form to
allow of this movement. The part 2 of the rearward body is connected by guide
plates or blades 3, 3, to the pipe, tube, case, or hollow guide 4, the office of such
guides or blades being, as already explained in the Specification of my former
Patent hereinabove mentioned, to gradually deflect and direct the water projected
from the propeller into a direction approximately parallel to the axis of the fixed
part of the rearward body. The part 2, the guide plates or blades 3, 3, and the
pipe, tube, case, or hollow guide 4, are 'rigidly connected together and are attached
to the vessel by the screws 10, 10, which take into thickened parts of the
hoops 11, 11, fitted round the hollow guide. The pipe, tube, case, or hollow guide 4
terminates at its after end in the plane, in which lies the after end of the fixed

page_text: part 2 of the rearward body, and is provided with two external curved plates or
guides 12, 12, (whose outlines, so far as they are visible in plan view, are defined
in Fig. 3 by k, l, m, n, o, p), so arranged that when the rudder with part 2b of
the rearward body is moved through more than a certain angle either way, one of
the said curved plates or guides will be moved into such a position as to partly
overlap the pipe, tube, case, or hollow guide, and also the part 2 of the rearward
body, and thus to deflect or direct the stream of water issuing from the guide into
a direction approximately parallel to the axis of the part 2 of the rearward body.
The external curved plates or guides 12, 12, are pivotted each at its lower
extremity to a stud or pin 13 attached to the hollow guide 4, the hole in the
plate being large enough to allow of a little play, for which purpose also the
stud is made longer than would otherwise be necessary, as shown. At their
upper extremities the plates 12 are guided by their respective slots 14, 14, each
working on a stud 15, as shewn clearly in Figs. 2 and 3. The plates 12 are
worked or operated by cranks or arms 18, 18, attached to short vertical shafts
20, 20, upon which are bifurcated levers 19, 19, the movements of which are
commanded by the tiller. 16 is a second tiller or arm fixed upon the rudder head
or axis 8, and provided with a downwardly projecting stud and roller 17, whose
office is to engage with one or other of the bifurcated levers 19 (the outline of
which follows the line a, b, c, d, e, f, g, h, i, Fig. 3), and to operate the curved
plates or guides 12, 12, when the rudder is put over beyond a certain number of
degrees. When the rudder is fore and aft, or nearly so, the curved guides or
plates 12, 12, are maintained in position around the hollow guide 4 by the arms 19*
of the bifurcated levers 19, bearing with their anti-friction rollers 21, 21, against
the curved portions of the locking plate 22 on the rudder head or axis.
In front of the pipe, tube, case, or hollow guide 4 is a grid or guard 23 made in
two parts meeting in a vertical plane about coincident with the longitudinal centre
line of the vessel, each of which is connected to the vessel by two links 24, 24.
each jointed at 24 to the vessel, and at 24b to its respected grid, of such length
that the half grids may be drawn away from the screw and laid on deck without
disconnecting them from their attachments.
In the Drawings my above-described propelling apparatus is shewn in the
normal position, that is to say, the attitudes of the respective parts are such as
would obtain supposing the vessel to be going ahead in a straight line in smooth
water. When the vessel under like conditions is turning in curves of long radius
there is no alteration, except that the rudder and after part of the rearward body
are put over to a slight angle with the axis of the vessel in one direction or the
other.
When however it is desired to make a sudden or rapid turn the operation is as
follows:-The tiller 9 is put hard over, turning the rudder head or axis 8 and
lever 16 with it. This motion carries the curved portion of the locking plate 22
beyond the roller on one of the levers 19 (say the starboard lever) and releases
that lever, but at or about the moment the arm 19. becomes free the stud and
roller 17 engage with the bifurcated end of the lever, and moving forward enter
its slot g, h, i, thereby turning the lever 19 and with it the vertical shaft 20 con-
nected to it, and the corresponding crank or arm 18. The crank or lever 18 of
each shaft 20 engages with a spherical headed stud 25 fixed in the corresponding
guide plate 12, so that when either of the levers 19 above described is actuated
there' results a rapid movement of the said guide plate which is pivotted on the
stud 13 and guided by the stud 15 outwards and backwards. The action of the
lever on the guide 12 is first to move it away from the hollow guide 4 and to carry
it aft, and then to press its forward edge around the after end of the hollow
guide 4, and to place it in such a position with relation to the hollow guide as to
direct the issuing water in a line approximately parallel to the axis of the
body 2b
Having thus described the nature of the said Invention, and the manner in
which it is to be or may be performed or carried into practical effect, I would have

page_text: it understood that what I consider to be novel and original, and therefore claim as
secured to me under the Letters Patent herein before first in part recited is,-
1. In apparatus for propelling and steering ships or vessels, wherein a propeller
has behind it in line with its boss a rearward body having a gradually increasing
diameter or width for a short distance, and afterwards a gradually diminishing
diameter or width to its rearward end, making the said body in two or more
lengths, and mounting the rearward part of the same on pivots or axes so that it
can be moved to port or to starboard after the manner of a rudder, substantially as
described.
2. In apparatas, such as above mentioned, for propelling and steering ships or
vessels, combining the moveable portion of the rearward body with a rudder so as
to form a combined water guide and steering apparatus, substantially as described
and illustrated.
3. In apparatus for propelling and steering ships or vessels, the use in combi-
nation of a propeller, a rearward body formed in two or more parts, the after part
or parts being moveable to port or to starboard after the manner of a rudder, a
pipe, tube, case, or hollow guide and curved plates or guides able to turn on suitable
pins, and to be operated from the tiller so as to deflect water issuing from the said
pipe, tube, case, or hollow guide into a direction approximately parallel with the
axis of the moveable after part of the rearward body when it is put hard over,
substantially as described.
4. The use of a grid or guard to prevent the fouling of steering and propelling
apparatus, constructed, arranged, and operating substantially as described and
shewn.
5. The combined apparatus for propelling and steering ships and vessels, con-
structed, arranged, and operating as described and shewn.
In witness whereof, I, the said John Isaac Thornycroft, have hereunto set
my hand and seal, this Twentyeighth day of October, in the year of our
Lord One thousand eight hundred and eighty one.
JOHN ISAAC THORNYCROFT. (L.S.)