IMPROVE- MENTS IN GOVERNORS FOR MARINE ENGINES
Year: 1874

page_text: LETTERS PATENT to Thomas Harcourt Thompson, of Holyhead, in the
County of Anglesea, Civil Engineer, for the Invention of "IMPROVE-
LETTERS PATENT to Thomas Harcourt Thompson, of Holyhead, in the
County of Anglesea, Civil Engineer, for the Invention of "IMPROVE-
MENTS IN GOVERNORS FOR MARINE ENGINES."
Sealed the 19th January 1875, and dated the 25th September 1874.
PROVISIONAL SPECIFICATION left by the said Thomas Harcourt.
Thompson at the Office of the Commissioners of Patents, with his
Petition, on the 25th September 1874.
I, THOMAS HARCOURT THOMPSON, of Holyhead, in the County of
Anglesea, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN GOVERNORS FOR MARINE ENGINES," to be as
follows:-
In a rough sea the propellers of steam ships are liable to become at
any moment partially or entirely uncovered by the water. This pro-
duces racing" in the engines, to the great detriment of the machinery
and the structure of the ship, besides causing considerable loss of power,

page_text: and serious annoyance to those on board. It is in order to prevent
racing that these improvements in marine governors are designed.
My Invention mainly consists, 1st, of a throttle, equilibrium, or other
suitable stop valve in the steam pipe, actuated by a rod with a piston at
its other end, working in a cylinder connected by hydrostatic connec-
tions with another cylinder and piston or other apparatus placed near
the propeller; 2nd, of the said cylinder and piston or other apparatus,
to be hereafter more particularly described) communicating freely with
the outside water near the propeller.
In carrying out my said Invention into practice in an ordinary screw
stcamer I place a horizontal cylinder as near the stern as possible,
with a branched pipe leading from the aft head of the cylinder into the
sea on each side of the vessel. The pipe is usually of a T form with a
three-way valve at the junction, so that by turning round the valve I
can entirely cut off the connection between the outside water and the
apparatus. Inside the cylinder I place a piston of wood, or other
suitable material, fitting very loosely into the same, but with three or
more guide wheels, rubbing surfaces, or points on its circumference
bearing against the sides of the cylinder. Firmly fixed in a water-tight
manner to the piston at one end, and to the cylinder covers at the other
end, on each side of the said piston, I place a waterproof corrugated
flexible cylinder or cone of either india-rubber, canvas, and waterproof
composition, or other suitable substance, with corrugations somewhat
similar to those of an ordinary concertina, so that it can be pulled out
and in. These clastic corrugated cylinders I will hereafter designate as
"sacks" for the sake of brevity.
The forward sack will be generally made much smaller than the aft
one in diameter. I prefer to fix these sacks to the cylinder ends by
flanges screwed up between those of the cylinder and covers. From the
forward cylinder cover I lead a metallic or other pipe in any convenient
manner to the bottom of another cylinder placed vertically, and open at
the top. In this cylinder works a piston either with ordinary packing,
and water-tight, or fitting loosely in the cylinder, but with tight bearing
surfaces or wheels, as in the stern cylinder, and a single sack similar to
those in the said stern cylinder firmly fixed in a water-tight manner to
both the piston & the cylinder bottom.

page_text: This piston has a rod projecting upwards, actuating, directly or other-
wise, the cut-off or throttle valve in the steam pipes. Through a valve
or other arrangement in the piston the water or other liquid is intro-
duced to fill the pipe (and sacks at each end of it), and form a hydrostatic
connector.
The piston rod is slotted at one point, and a lever pivotted to some
point on the ship's bulkhead, or other firm support, passes through it,
and rests on the bottom of the slot of the piston rod. On the free end of
this lever (which projects horizontally when the piston is in the centre of
its stroke) there is a heavy weight, capable of adjustment as regards its
position in the length of the lever either by screwing it forward or back-
ward, or in any other manner.
Sometimes, instead of the piston rod being slotted, it is made in two
parts screwed with a right and left hand thread respectively into a double
nut, so as by turning the nut to regulate the length. The weighted
lever then is slotted, and rests on the nut.
The manner of action is as follows:-The three-way cock being
open, so as to allow the sea water free axis to the larger horizontal
sack, there is a strong pressure or head of water upon the piston when
the adjacent propeller is covered. This expands the sack, and puts an
increased pressure on the smaller sack, tending to compress it, and force
the water through the pipe into the vertical sack, which, expanding,
presses up the piston & rod (together with the weighed lever), & thus
opens the throttle or equilibrium valve. Should however the head
of water be removed from the stern cylinder (as it will be whenever
through bad weather and consequent movement of the vessel the stern
(& propeller) is nearly uncovered) very little pressure will be exerted
on the piston in the horizontal cylinder on its side next the stern, and
the pressure of the weighted lever on the vertical sack compressing the
latter will force the water back through the pipe into the smaller sack
in the horizontal cylinder. The vertical piston rod thus descending
with the vertical lever shuts the throttle or other valve, & cuts off the
steam from the cylinder. The weighted lever is partly supported by a
helical or other spring, & I also put an escape valve in the bottom of
the horizontal cylinder to let out any water that by any chance might
leak from the sacks therein.
In some cases it may be preferable, instead of using sacks in the stern
cylinder, to use two cylinders on the same centre line, one much smaller

page_text: than the other, and open at the ends nearest each other. The pistons
in these cylinders must be made water-tight, (& be rigidly connected
with each other, and thus form an arrangement similar in principle to
the aforesaid sacks, et cetera, but while simpler in detail quite as
expensive, and developing much more friction. I prefer the other a
arrangement.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Harcourt Thompson in the Great Seal
Patent Office on the 24th March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HARCOURT THOMPSON, of Holyhead, in the County of Anglesea, Civil
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Twenty-fifth day of September, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Thomas Harcourt Thompson,
Her special licence that I, the said Thomas Harcourt Thompson, my
executors, administrators, and assigns, or such others as I, the said
Thomas Harcourt Thompson, 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, usc, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "IMPROVEMENTS IN GOVERNORS FOR MARINE
ENGINES," upon the condition (amongst others) that I, the said Thomas
Harcourt Thompson, my executors or administrators, by an instru-
ment 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

page_text: 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 Thomas Harcourt Thompson, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawings, and to the letters of reference marked therein, that
is to say :-
My Invention relates mainly to an arrangement of governor for pre-
venting "racing" in marine engines by cutting off the steam or other
source of motive power from the engines whenever the propeller becomes
sufficiently denuded of water to cause racing with a full head on of steam
or other motive power.
It consists usually in placing a throttle, equilibrium, or cut-off valve in
the steam pipe, and if necessary also in the exhaust pipes, actuated by a
rod having a piston (or its mechanical equivalent) hydrostatically con.
nected to another piston or its equivalent, working against the pressure
of the outside water near the propeller.
In carrying out my said Invention into practice in an ordinary screw
steamer I place a horizontal or vertical cylinder or box A as near the
stem as possible with a branched pipe B leading from the bottom of
the after part of the same into the sea on each side of the vessel. The
pipe is usually of a T form with a three-way valve C at the junction, so
that by turning round the valve I can entirely cut off the connection
between the outside water and the apparatus. Inside the cylinder or
box I place a piston D of wood, or other suitable material, fitting very
loosely into the same, but with three or more guide wheels or rubbing
surfaces or edges on its on its circumference bearing against the sides and
bottom of the cylinder or box. Firmly fixed in a water-tight manner to
the piston at one end, and to the cylinder or box covers at the other end,
on each side of the piston D I place a waterproof corrugated flexible
cylinder or cone E, F, of either india-rubber, canvas, and waterproof
composition, or other suitable substance, with corrugations somewhat
similar to those of an ordinary concertina, so that it can be pulled out
and in. These elastic corrugated cylinders I will call hereafter "sacks"
for the sake of brevity.

page_text: The latter has a rod K projecting upwards, actuating the cut-off or
throttle valve K, directly or otherwise. Through a valve or other
arrangement in the piston I the water or other liquid is introduced to
fill the pipe G and sacks F and J, and form a hydrostatic connection..
The piston rod K is in two pieces screwed by a right and left hand
screw respectively into a double nut O, so that by turning the nut the
length of the piston rod can be regulated. Resting on this nut I place
a slotted lever L encircling the piston rod, and with one end joined to
some point on the ship's bulkhead or other firm support the other end
of this lever (which projects horizontally when the piston is in the centre
of its stroke). I place a heavy weight P, capable of adjustment as
regards its position on the arm or lever L either by screwing it forward
or backward, or in any other manner.
The manner of action is as follows:-The three-way cock C being open,
so as to allow the sea water access to the larger sack E in the box or
.cylinder A, there is a strong pressure or head of water upon the piston D
when the adjacent propeller is covered. This expands the sack E, and
puts an increased pressure on the smaller sack F, tending to compress it
and force the water through the pipe G into the vertical sack J, which,
expanding, presses up the piston I and rod K, together with the
weighted lever, and thus opens the throttle or equilibrium valve N.
Should however the head of water be removed from the sack E, as it
will be whenever through bad weather and the consequent movement of
the vessel the stern and propeller are nearly uncovered, very little
pressure will be exerted on the piston D of the stern cylinder from the
larger sack E. The pressure of the weighted lever on the lever J com-
pressing the latter will force the water back through the pipe G into

page_text: the smaller sack F in the stern cylinder A. The vertical piston rod K
thus decending with the weighted lever shuts the throttle or equilibrium
valve N, and cuts off the steam from the cylinder. The weighted
lever L is partly supported by a helical or other spring M. I also put
an escape valve P in the stern cylinder A to let out any water that by
any chance might leak from the sacks therein, and I occasionally con-
struct said cylinder in two parts with a longitudinal division, so that the
top can be raised to examine or repair the sacks inside.
Now the points I claim as my Invention are,-
-
1st. The sacks F & E differing usually in sectional area on each
side of the piston D, so as to obtain an increase of pressure in the tube G
beyond what exists in sack E for the purposes described (or any
mechanical equivalent for the same, such as the two cylinders on one
piston rod described in the Provisional Specification.)
2nd. The mode of dispensing with stuffing boxes and friction by the
use of the elastic sacks for the purpose specified.
3rd. The hydrostatic conductor of soapy water, or other suitable fluid,
water-tight and isolated, from the exterior water conducting the pressure
from mechanism at the stern of the vessel to the equilibrium valve for
the purposes described.
In witness whereof, I, the said Thomas Harcourt Thompson, have
hereunto set my hand and seal, the Twenty-second day of
January, in the year of our Lord One thousand eight hundred
and seventy-five.
THOMAS HARCOURT THOMPSON. (L.S.)
Witness,
W. PHILLIPS THOMPSON,
-
Patent Agent,
6, Lord St.,
Liverpool.