IMPROVEMENTS IN SHIPS' STERN POSTS AND RUDDERS
Year: 1881

page_text: LETTERS PATENT to William Cooke and Daniel Mylchreest of Liverpool in
the County of Lancaster Marine Engineers and Naval Architects, for an
Invention of "IMPROVEMENTS IN SHIPS' STERN POSTS AND RUDDERS"
PROVISIONAL SPECIFICATION left by the said William Cooke & Daniel
Mylchreest at the Office of the Commissioners of Patents on the 29th December
1881.
WILLIAM COOKE and DANIEL MYLCHREEST of Liverpool in the County of
Lancaster, Marine Engineers and Naval Architects. "IMPROVEMENTS IN SHIP'S
STERN POSTS AND RUDDERS
"
The object here is to provide stern posts and rudders so constructed that the
said rudders may be easily shipped and unshipped without passing through the
counter and at the same time be cheaper and more durable than those heretofore
in use.
For that purpose we construct stern posts each with bosses or cheeks having
slots or openings therethrough into which the rudder fits and in which it is securely
held though capable of being moved freely in the directions required for steering.
The slots or openings through the bosses or cheeks are cylindrical next the stern
posts for nearly three quarters of a circle and aft of that they spread angularly
outwards the angle of opening being 90° or thereabouts. The stern post is preferably
made with a semi cylindrical groove extending from one boss or cheek to the next
and concentric with the cylindrical portion of the slots or openings therethrough.
A rudder is made in one piece preferably in the manner for which we obtained
Provisional Protection No. 4803 of the year 1881, with pieces along the front edge
so curved and of such a size as to fit into and fill or nearly fill the cylindrical
portions of the slots or openings in the bosses or cheeks on the stern post. The
said pieces are advantageously formed by prolonging the rudder shaft in which
case the said shaft is flattened at suitable intervals to allow of the rudder being
passed into position through the openings between the bosses or cheeks. The
bosses or cheeks act as stop cleets and prevent the rudder from being moved over
too far.
If desired the rudder is constructed with slotted bosses or cheeks and the stern
post with holding pieces to fit into the said bosses or cheeks.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Cooke & Daniel Mylchreest in the Great Seal Patent
Office on the 29th June 1882.
"
WILLIAM COOKE and DANIEL MYLCHREEST of Liverpool in the County of
Lancaster, Marine Engineers and Naval Architects. IMPROVEMENTS IN SHIPS
STERN POSTS AND RUDDERS
"
The object here is to provide stern posts and rudders so constructed that the
said rudders may be easily shipped and unshipped without passing through the
counter and at the same time be cheaper and more durable than those heretofore
in use.
For that purpose we construct stern posts each with bosses or cheeks having
slots or openings therethrough into which the rudder fits and in which it is securely
held though capable of being moved freely in the directions required for steering.
The slots or openings through the bosses or cheeks are cylindrical next the stern
post for nearly three quarters of a circle and aft of that they spread angularly
outwards the angle of opening being 90° or thereabouts. The stern-post is preferably
made with a semi-cylindrical groove extending from one boss or check to the next
and concentric with the cylindrical portion of the slots or openings therethrough.
A rudder is made in one piece, preferably in the manner for which we obtained
-Letters-Patent No.4803 of the year 1881, with pieces along the front edge so
curved and of such a size as to fit into and fill or nearly fill the cylindrical
portions of the slots or openings in the bosses or cheeks on the stern post. The
said pieces are advantageously formed by prolonging the rudder shaft in which
case the said shaft is flattened at suitable intervals to allow of the rudder being
passed into position through the openings between the bosses or cheeks. The
bosses or checks act as stop cleats and prevent the rudder from being moved over
too far.
If desired the rudder is constructed with slotted bosses or cheeks and the stern
post with holding pieces to fit into the said bosses or cheeks.
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a plan, Fig. 2 a side elevation and Figs. 3 and 4 sections to an enlarged
scale at the lines A. A. B. B. of a stern post and rudder suitable for sailing ships or
vessels and for steam ships not having a propeller at the stern. a stern post,
b bosses cheeks or clips. c slots or openings through the said bosses cheeks or
clips, semi cylindrical groove extending along the stern post from one boss check
or clip to the next; e rudder made in one piece substantially in the manner
described in the Specification to British Letters Patent No. 4803 of the year. 1881
granted to us. The rudder may be otherwise made frudder shaft or stock pro-
longed from the top to the bottom of the rudder blade, g flattened portions of the
shaft or stock so disposed as to leave picces i to fit into and fill the slots or
openings c. The flattened portions g allow of the rudder being shipped and
unshipped without its being drawn through the counter as would otherwise be
necessary. The lips of the bosses cheeks or clips b forming the angular faces of
the slots or openings c act as stop cleats and prevent excessive angular motion of
the rudder, as will be seen by the dotted lines Fig. 1.
Instead of the rudder shaft or stock extending from end to end of the rudder
blade it may terminate at the upper end thereof as shown in Fig. 5 and pieces i
to fit into the slots or openings of the bosses cheeks or clips may be cast welded, or
otherwise secured to the rudder blade at the required distances apart.

page_text: Fig. O is a plan view, Fig. 7 a side elevation and Figs. 8 and 9 are sections on
an enlarged scale at the lines C, C-D D of a stern post and rudder suitable for
screw steam ships. Here the pieces i only nearly or partly fill the slots or
openings and packing or wearing pieces are provided to fit into and fill the
otherwise vacant spaces. The sizes of the bosses i and slots or openings c are such
that when the packing or wearing pieces are removed the rudder may be freely
shipped or unshipped without being raised. are bearing flanges for packing or
wearing pieces.
Fig. 10 is a section showing how a thinner packing or wearing piece than that
illustrated in Figs. 6. 7. 8 and 9 may be used without interfering with the free
shipping and unshipping of the rudder, in this case the bosses checks or clips are
provided with horns or projections & and openings are formed in the rudder blade
to allow of angular motion.
Fig. 11 is a sectional view showing a thin packing or wearing pieco where the
rudder must be slightly raised before it can be shipped and unshipped. In this
case the packing or wearing pieces may be secured to the pieces i.
In all the above views the angular faces of the bosses cheeks or clips act as
stop cleats. Separate stop cleats may be provided if desired.
Fig. 12 is a side clevation, and Fig. 13 a view half in section and half in
elevation of a stern post and rudder in which the positions of the bosses cheeks or
clips b and the pieces i are reversed; that is to say, the said bosses cheeks or clips
are secured to or form part of the rudder and the pieces which fit into the slots
or openings through the said bosses cheeks or clips are attached to or formed with
the stern post, otherwise the construction is similar to that described under Figs.
6. 7. 8 and 9 and the same letters denote like parts. n are stop cleats.
Fig. 14 is a sectional view in which the stern post is oval in section and is
surrounded at the required intervals with packing or wearing pieces j.
Fig. 15 is a sectional view showing a rectangular stern post with pieces i cast or
otherwise secured thereto.
When the pieces i are formed with or secured to the stern post, separate stop
cleats are provided.
It will be evident that the stern posts may be of any suitable section and that
our improved stern posts and rudders are suitable both for steam or sailing ships
or vessels.
Having now described and illustrated the said Invention in such manner that
others will be enabled to carry our improvements into effect, we claim :-
Constructing and combining stern posts and rudders substantially in the manner
herein described for the purpose setforth.
In witness whereof I the said Daniel Mylchreest have hereunto set my
hand and seal this Twenty seventh day of June in the year of our Lord
One thousand eight hundred and eighty two
DANIEL MYLCHREEST.
(L.S.)