INPROVENPETS IN MARINE STEAM ENGINES
Year: 1868

page_text: LETTERS PATENT to Ebenezer Kemp and Henry Gourlay, both of
Dundee, in the County of Forfar, North Britain, Engineers, for the
Invention of "INPROVENPETS IN MARINE STEAM ENGINES"
PROVISIONAL SPECIFICATION left by the said Ebenezer Kemp and
Henry Gourlay at the Office of the Commissioners of Patents, with
their Petition, on the 21st April 1868.
We, EBENEZER KEMP and HENRY GOURLAY, both of Dundee, in the
County of Forfar, North Britain, Engineers, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN MARINE STEAM ENGINES," to be
as follows, that is to say :-
This Invention relates to the constructing of marine steam engines
so that the stroke of the cylinder piston may be longer than twice
the radius of the crank; and the improved arrangements embodying
this feature are more particularly suitable for driving screw propellers.
In carrying out the Invention the piston rod is jointed to a lever
or to a combined pair of levers which has the connecting rod from
the crank jointed to it at a point nearer to its fulcrum. This con-

page_text: struction admits of very convenient dispositions of the various parts of
the engines, and it is applicable with inverted vertical cylinders, with
horizontal cylinders, or with cylinders which are more or less inclined,
whilst it is also applicable with plain cylinders or with combined high-
pressure and low-pressure cylinders.
In one convenient series of modifications the lever is arranged so as
with suitable radius rods to form a parallel motion for the piston
rod, the bearings of the fulcrum being arranged to have a short traverse
in suitable guides in the framing. If preferred, however, the ordinary
guides may be provided for the piston rod crosshead, and it may be
connected to the lever by links. The air pump may be opposite to
and in the line of the steam cylinder, and it may be worked by a
continuation of the piston rod. The air pump and the other pumps may
however be arranged in any positions that may be considered most
convenient as the rods for working them may be connected to the
lever in a variety of ways.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ebenezer Kemp and Henry Gourlay in the Great
Seal Patent Office on the 20th October 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, EBENEZER
KEMP and HENRY GOURLAY, both of Dundee, in the County of Forfar,
North Britain, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of April, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-
first year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said Ebenezer Kemp and Henry Gourlay, Her
special licence that we, the said Ebenezer Kemp and Henry Gourlay,
our executors, administrators, and assigns, or such others as we, the said
Ebenezer Kemp and Henry Gourlay, our 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 MARINE STEAM ENGINES," upon

page_text: the condition (amongst others) that we, the said Ebenezer Kemp and
Henry Gourlay, our executors or administrators, by an instrument in
writing, under our, 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 we, the said Ebenezer Kemp and Henry
Gourlay, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement in writing, reference
being had to the accompanying Drawings, that is to say :-
Our said Invention comprises various designs or modes of arranging
and combining the parts of marine steam engines, in all of which
designs the stroke of the cylinder piston is longer than twice the
radius of the crank; and our improved arrangements embodying this
feature are more particularly suitable for driving screw propellers.
In carrying out our Invention the piston rod is jointed or connected to
a lever or to a combined pair of levers which has the connecting rod
from the crank jointed to it at a point nearer to its fulcrum. This
construction admits of very convenient dispositions of the various parts
of the engines, and is applied by us with inverted vertical cylinders,
with horizontal cylinders, or with cylinders which are more or less
inclined, whilst we also propose to apply it with ordinary cylinders or
with combined high-pressure and low-pressure cylinders.
And in order that our said Invention and the manner of performing
the same may be properly understood, we have hereunto appended two
Sheets of explanatory Drawings, to be herein-after referred to, and of
which Sheet 1 represents our various designs or arrangements on a small
scale, whilst Sheet 2 represents one of those designs in an enlarged and
more detailed manner, so as to serve as an example from which makers
of marine engines will be enabled to construct any of the arrangements
in a complete manner. The same reference numerals are used to mark
the same or like parts in all the Figures.
Figures 1 to 9, on Sheet 1 of the Drawings, are elevation diagrams,
showing the main features of our various designs; Figure 10, on Sheet 2,
is a sectional side elevation, and Figure 11 is a transverse vertical section
of a set of screw propeller engines as constructed according to design

page_text: No. 3 (Figure 3), which differs from design No. 1 merely in having the
cylinder 1 and some other parts disposed vertically instead of being
slightly inclined, as in Figure 1. In all the designs the framing is
adapted to the arrangement of the other parts in as simple a manner as
possible, and as will be easily understood from the Drawings.
In designs Nos. 1 and 3 the piston rod 2 is bolted to the air pump
plunger 3, the air pump 4 being in the same axial line as the
cylinder 1. The piston rod 2 is connected by links 5, jointed on a
cross pin fixed in the top of the plunger to a pair of plate levers 6,
having a fulcrum pin 7 carried in bearings on the framing. The lateral
movement of the links 5 being very slight, the piston rod 2 does not
require more guiding than is afforded by the stuffing boxes and pistons
of the cylinder 1 and air pump 4. The pair of levers 6 has fixed
across it at a point nearer the fulcrum than the points of connection
of the piston rod links 5 a pin 8, on which is jointed the upper end of
the connecting rod 9 that transmits the power to the crank 10 of the
main shaft 11. The levers 6 are prolonged beyond the fulcrum 7 to
work the feed and bilge pumps 12. The engines are represented as
provided with surface condensers 13, which are very conveniently
arranged in a part of the framing supporting the steam cylinders 1, and
the cooling water may be forced or drawn through such condensers by
one of the pumps 4 opposite the steam cylinders 1, the other being in
that case made large enough to serve as an air pump for both cylinders.
The minor details of the arrangement will be easily understood from
Figures 10 and 11.
In design No. 2 the levers 6 are connected to radius links 14 and 15,
by which the piston rod 2 is guided in a straight line, and the
air pump 4 is inclined and worked by a pin on the levers 6 situated
so as to give the pump plunger a shorter stroke than that of the steam
pistons.
In design No. 4 provision is made for using a small cylinder on the
top of the large cylinder in order to admit high-pressure steam first to
the small cylinder and to afterwards expand it further in the large
cylinder. A separate cold water pump 16 is also arranged to be worked
from the lever 6. The addition of high-pressure cylinders and cold
water pumps may be applied to any of the designs.
In design No. 5 two pairs of levers 6 are introduced for actuating two
shafts 11 for twin screws from one set of steam cylinders 1.

page_text: In design No. 6 separate cylinders are arranged for actuating twin
screw shafts 11 through the intervention of levers 6.
In design No. 7 the condenser 13 is arranged on the opposite side of
the screw shaft 11 to that on which the steam cylinder 1 and air pump 4
are placed. The levers 6 may be prolonged over the condenser to work
air or cold water pumps.
In design No. 8 the steam cylinder 1 and air pump 4 are arranged
horizontally, and the connecting rod 9 between the levers 6 and shaft 11
is directed towards the steam cylinder instead of away from it, as in the
designs previously described.
Finally, in design No. 9 the steam cylinder 1 and air pump 4 are also
horizontal, whilst two shafts 11 for twin screws are arranged to be
actuated from one pair of levers 6 vibrating midway between them, and
with connecting rods 9 proceeding from them in opposite directions.
Having thus particularly described our said Invention, and the
manner in which the same is to be performed, we have to state that
we do not restrict ourselves to the precise details herein described or
delineated; but that what we believe to be novel and original and claim
as the Invention secured to us by the herein-before in part recited
Letters Patent is, the arranging and combining of the parts of marine
steam engines, substantially according to the various designs herein
described and delineated; and more particularly the interposing of a
lever (6) between the piston rod (2) and connecting rod (9), so as to
reduce the movement of the latter, combined with the placing of the
pumps as herein-before described.
In witness whereof, we, the said Ebenezer Kemp and Henry
Gourlay, have hereunto set our hands and seals, this Seventeenth
day of October, in the year of our Lord One thousand eight
hundred and sixty-eight.
EBENEZER KEMP. (L.S.)
HENRY GOURLAY. (L.S.)